​Answers to Frequently Asked Questions (FAQs) About Various Billiards and Pool Topics
Categories

A - C D - G H - P Q - S T - Z

Deflection

See "squirt" section

For more info, visit billiards.colostate.edu

Draw

(external web-links) for more information:
see Section 4.02 in The Illustrated Principles of Pool and Billiards,
Disc I of the Video Encyclopedia of Pool Shots, and Disc I of the Video Encyclopedia of Pool Practice

Advice and drills
How can I improve my draw stroke?
In general, to get good draw action, you must hit the CB both low and hard. Probably the best advice to accomplish this is to keep your grip relaxed and smoothly accelerate the cue into the ball (i.e., don't jerk or rush the transition from the final backstroke to forward stroke) to create good follow-through. A longer bridge length can help create more power without jerkiness. A closed bridge might help you achieve a lower tip position without adding cue elevation (which can decrease accuracy), especially if you have large hands. More stroke advice can be found under "stroke" section. Also, make sure you have a good tip that is well shaped and textured so it holds chalk. Also, be sure to chalk up before each shot.

If you are having trouble with your draw stroke, make sure you are being careful with the following:

• Don't elevate the cue. This makes your stroke more awkward and less accurate.
• Don't rush the transition between the final backstroke and the final forward stroke. Go back slowly, pause, and accelerate smoothly for best accuracy and power.
• Don't tighten your grip during the stroke. This will reduce your power and tip contact point accuracy.
• Don't drop your elbow before CB contact. This will make the tip hit the CB higher than you are aiming, reducing draw. Also, when the elbow drops, it can also tend to move sideways, which can throw the shot off line.
• Don't jerk the cue back after the hit. Follow through with a smoothly accelerating stroke. You have time to lift, pull back, or move the cue sideways, after you follow through, to get out of the way of the drawing CB.

Here are good video demonstrations of draw shot technique advice, physics effects, and game-situation examples:

And in below listed YouTube videos:
Draw shots(physics)
Draw shots(examples)
and here's a good progressive-practice drill to help you improve your draw shot technique, from Disc I of the Video Encyclopedia of Pool Practice (VEPP) (external web-link):
YouTube(practice shots)
and here's a good video demonstration for power draw advice, from Disc I of The Video Encyclopedia of Pool Shots (external web-link):
YouTube(shot technique advice)

Anytime you practice or do experiments with draw shots, it is important to verify that you are hitting the CB where you think you are. The best way to do this is to use a marked ball (for example, a Jim Rempe CB or an Elephant Practice ball) or a striped ball, and note the location of the chalk mark on the ball after each shot. Just make sure you align the markings on the ball with the line of action of the cue (for example, see the 9-ball stripe in Diagram 1b (Download)). People are often surprised by how high the actual tip contact point is on the ball despite how low they might think they are aiming. Sometimes, people just don’t aim low enough on the CB. Sometimes people drop their elbow during the stroke, before tip contact. This brings the tip up, and you get less draw. If you tighten your grip during the stroke, the tip will drop and you might scoop the CB in the air. Always look at the mark on the CB after the shot ... the chalk mark never lies!

It also helps (a lot!) to have a very slick and fast cloth. It is a lot easier to draw the ball on a slick and fast cloth! For more info, see: cloth and cue ball effects in this section.

For more information and advice, see the following series of instructional articles dealing draw shot physics, aiming, applications, technique, and drills: (Downloads)
"Draw Shot Primer - Part I: physics" (BD, January, 2006).
"Draw Shot Primer - Part II: aiming" (BD, February, 2006).
"Draw Shot Primer - Part III: using the trisect system" (BD, March, 2006).
"Draw Shot Primer - Part IV: game examples" (BD, April, 2006).
"Draw Shot Primer - Part V: how to achieve good draw action" (BD, May, 2006).
"Draw Shot Primer - Part VI: draw shot practice drill" (BD, June, 2006).
"Draw Shot Primer - Part VII: tips of english" (BD, July, 2006).

Also see the physics-based draw shot advice in this section.

from Rod (concerning causes for miscuing and "scooping" the ball):
The number one reason. Your grip hand tightens up, in turn so does your arm and shoulder. When that happens it elevates the butt of the cue. Guess what comes next? The tips drops and you hit too far below center. The cue ball goes flying.
If at the same time (which happens a lot) your stroke swerves to either side, then the cue ball squirts off to the side. Nothing worse that that nasty miscue sound.
Tight muscles are shorter and probably slower, relaxed muscles are longer. Stay relaxed, not only will you improve your draw stroke, it will improve every stroke.
Striking the c/b accurately is premium. You need to hit where you addressed the c/b to make the shot come off as planned. If your grip tightens up --- well you know the answer.

from RSB_FAQ:
You will probably receive all sorts of contradictory advice on this one. The only real requirement is that you hit the ball low. If the object ball is far away, you will also need to hit the ball hard to keep back spin (also known as draw or screw) on the cue ball, as the cloth rubs the spin off. Some things to keep in mind: You must chalk your tip well; most players don't. A shorter bridge (hand to cue ball spacing) will let you hit where you want more accurately. If your elbow is pumping up and down, hitting the intended spot on the cue ball is more of a challenge. Do you jump up at the end of the shot? Do you follow through so the tip ends at least a ball diameter or two beyond the original position of the cue ball, or do you jerk abruptly to a stop at the instant of contact?

from Bob_Jewett (concerning a slightly elevated cue, which causes cue ball hop):
The simple theory is that the cue ball loses a fixed number of RPMs per second on its way to the object ball. If the cue ball is hopping on its way to the object ball, it will lose draw only on the landings, but the simple theory says that the total loss of draw on the way to the object ball will be about the same.

The theory also says that if the cue ball is hopping with draw off an object ball, or maybe hopping from a masse shot, it will travel in straight lines between the landings as seen from above, but the path will take abrupt turns at the times of the landings.

One consequence to practical play of the first paragraph is that to get best draw for a particular stick speed off a distant ball it is sometimes better to cue higher on the cue ball. The closer to center you hit, the faster the cue ball will be going at the start. It is a balance between getting there quickly and not losing as many RPMs and starting with more RPMs and losing more due to the slower cue ball travel.

Bridge length effects
What bridge length should I use to get good draw action?
A longer bridge length can help create more power with less jerkiness; but with more length you will get less tip-placement accuracy. Every individual will have an optimal length where these trade offs are balanced.

More information about bridge length effects can be found in "Fundamentals - Part IV: bridge length" (Download) (December, 2008) and on the bridge length in the "bridge" section.

from jsp:
The equation for obtaining maximum draw is simple and involves only two things. The cue tip should hit the CB as low as possible and the cue tip should be traveling as fast as possible, all without miscuing. That's all. Bridge length comes into the equation only to the extent as how much it affects tip placement and speed.

A longer bridge might help you obtain greater cue tip velocity on impact (assuming a constant cue acceleration and that stroke length is in proportion to bridge length). However, a shorter bridge might help you in tip placement accuracy such that you more reliably hit the CB as low as possible without miscuing.

Precise cue tip placement is definitely harder to achieve than a high cue tip velocity. So for a beginner, I would recommend a shorter bridge length to obtain greater draw.

from Mike Page:
A consequence of this is for the really best players among us, a bridge length close to their own-break shot bridge length might give them maximum draw. This is the bridge length that evidently gives them maximum speed with control. For many of the rest of us, the quality of our tip placement deteriorates more rapidly with bridge length and our optimal bridge length for maximum draw would be shorter. For new players it would be very short, imo.

Cloth and cue ball effects
How does the condition of the table cloth and the cue ball affect draw action?
It is easier to get more draw action on a "slick" cloth (i.e., a cloth with low sliding friction), because the cue ball retains more of its bottom spin on the way to the object ball. A "fast" cloth (a cloth with low rolling resistance), will allow the cue ball to roll farther after the draw takes.

If you want to simulate the effects of a "slick" cloth, or if you just want to impress your friends with dramatic draw, try spraying and/or wiping the cue ball with Silicone Spray (spray lubricant available at any hardware store). You will be able to draw like you've never drawn before.

To visualize the "drag" action of the cloth, see:

• HSV B.10 - MOFUDAT stroke drill follow and draw effects (YouTube)
• NV B.10 - Drag spin loss and sidespin persistence (YouTube)

The thickness of the cloth can also affect how the CB comes off the tip, especially with cue elevation. For more info, see:

• HSV B.44 - cloth compression and cue ball trajectory for draw shots of various elevations (YouTube)

from Patrick Johnson:​

Click/tap to enlarge

from Bob_Jewett:
It is important to distinguish between rolling friction and sliding friction. The two affect the cue ball in different ways and they are sometimes misunderstood. Sliding friction relates to the force from the cue ball sliding on the cloth. It causes draw to wear off and it allows draw or follow to take effect after the cue ball hits the object ball. Sliding friction can be reduced by getting new (slippery) cloth and by waxing the cue ball. Waxing is an easy experiment to do, and I recommend it to anyone who hasn't tried it yet.

Rolling friction tells you how quickly the cue ball slows down after it is rolling smoothly on the cloth. With low rolling friction, it takes the cue ball a long time to slow down. If you have one available, check out how long the ball rolls on a heated carom table.

All combinations of high and low values of these two kinds of friction are possible. The most extreme case of low/low I've tried was on a waxed linoleum floor. You can do amazing masse shots under such conditions. New carom cloth is the closest on-table example of this combination.

Low rolling resistance and high surface friction occurs sometimes on thin old cloth that's dirty and compressed. An extreme example would be a very hard rubber surface -- the ball would roll for a long time but there is no way you could keep draw on it.

High rolling resistance and high surface friction is what you often get in bars. Dirty, thick cloth, and dirty, rough cue balls.

The most important friction when trying to draw the cue ball is the friction between the cue ball and the cloth on the way to the object ball. That friction can wear off some, most or all of the backspin. You will seem to get a lot more draw by waxing the cue ball so that it loses less draw on the way to the object ball.

Once the cue ball contacts the object ball, the friction will allow the draw to take. Less friction just means that it will take longer for the cue ball to come up to full speed, but the final speed of the cue ball drawing back will be nearly the same regardless of the actual value of the friction ball-to-cloth.

One thing that is most noticeable about a slippery cue ball is the remarkable arc you can get when drawing a cut shot. Because the slippery cloth delays the action, you get a much wider arc.

... something that's a huge factor in many pool halls: the size of the cue ball. The cue ball wears down in play, and if the cue ball is smaller, it is also lighter and much, much easier to draw.

In the case of old cloth, the problem is nearly always that the cloth is sticky, which is to say that there is more ball-cloth friction and the draw wears off faster. Waxing the cue ball in such a situation will often restore new-cloth action for a while until the wax wears off.

from Patrick Johnson:
It's not true that the CB will lose more draw spin as it "peels out" on slipperier cloth - it loses the same amount of spin on any kind of cloth; it just takes a little longer on slippery cloth (see explanation below).

If the CB hits the OB with the same amount of backspin, then the cloth doesn't matter - the cue ball will draw back the same distance on slippery or sticky cloth. But sticky (nappy or dirty) cloth rubs off more of the CB's backspin on its way to the OB and slippery cloth rubs off less. That's why you have to put more backspin on the CB on sticky cloth and why the best cloth for draw is the fastest (slipperiest) cloth.

When the CB hits the OB with the same amount of backspin (or forward spin) it reacts differently on slippery and sticky cloth:
- On slippery cloth it will "peel out" for a longer time and take more time to pick up speed and start rolling naturally, but it will lose spin more slowly.
- On sticky cloth it will "peel out" for a shorter time and take less time to pick up speed and start rolling naturally, but it will lose spin more quickly.

Here's the interesting thing: these two effects balance out so that when the CB has stopped peeling out and starts rolling naturally it will be moving the same speed in both cases and therefore will draw back (or follow forward) the same distance. 

P.S. You point out an important distinction that many players don't get: cloth is faster/slower in two separate ways; sliding speed and rolling speed. Fast cloth is usually faster both ways, but not always to the same degree. Some cloth slides really well (so the CB retains lots of draw or follow spin on its way to the OB), but doesn't roll as far as you'd expect, and vice verse. "Slipperiness" (sliding speed) also affects the way balls react off the rails with sidespin.

reply from Jal:
... the cue ball will draw back a bit farther on slicker cloth, assuming its rolling resistance is at least the same or less than the stickier cloth's.

Cue elevation effects
Does it help to elevate the cue for draw shots?
It depends. See "Draw Shot Physics - Part IV: cue elevation effects" (Download) (BD, July, 2009) for more info.

Cue elevation can help create quick draw, but reduced accuracy and swerve are large factors. Also, the CB will hop more, which can result in overcutting a shot per jump shot over cut effects.

For more information, see cue elevation effects and technique advice under "cue" section.

Physics-based advice
What does pool physics offer for advice on draw shots?
Here's the list of conclusion, which can be found at the end of TP B.8 (Download) (all of the graphs referenced below are clearly labeled in the analysis if you want to check them out):

1. Generally, to get more draw, you must hit the cue ball harder and lower (see graphs A and G). No big surprise here!
2. More tip offset does not produce significantly more draw as you approach the miscue limit; so, generally, it is advisable to not hit too close to the miscue limit (see graphs A and G).
3. With larger drag distances, and for a given maximum cue speed, max draw occurs at less than maximum tip offset (at about 70%-80% tip offset). In other words, you don’t get more power draw by hitting closer to the miscue limit. However, 80% is still fairly close to the miscue limit (see Graphs G, Q, S, and U, and see the data on the previous page).
4. In general, with a draw shot with a medium desired draw distance, a slower cue speed with more tip offset will result in better draw distance control than a faster cue speed with less offset (see the slopes of the curves in Graphs A and G at a given draw distance).
5. Stop shots are much less sensitive to tip offset position than draw shots are. In other words, CB position is much easier to control with a stop shot, as compared to a draw shot (see Graphs G, H, I, N, and O).
6. For a short stop shot, slower speed offers slightly better control (see the overall slopes of the curves in Graph I). For longer stop shots, faster speed appears to offer slightly better stop control (see Graphs N and O); although, with more speed, the CB will drift sideways more if the OB isn't hit perfectly squarely.
7. For stun-through (small controlled follow) and stun-back (small controlled draw), a firmer hit closer to center offers better CB distance control (see Graphs L and M).
8. It is much easier to control draw distance on a new, slick cloth than it is on a "sticky" cloth, especially with lower-speed shots (see Graph T). The statement assumes the player is equally well "adjusted" to each cloth condition. Any player will need to adjust when playing under different cloth conditions.
9. It is easier to draw the ball on slick cloth, and faster cloth allows for greater draw distances.

For more info and illustrations, see "Draw Shot Physics - Part I: basics" (Download) (BD, April, 2009) and "Draw Shot Physics - Part II: examples" (Download) (BD, May, 2009).

With a straight draw shot (with no cut angle), the amount of draw is determined solely by the amount of CB spin at contact with the OB. This is the topic of TP B.8 (Download). In TP B.9 (Download), I look at both spin and the spin-to-speed ratio. Examples where spin-to-speed ratio is more important than spin are when ...

1. ... you don't want to hit the OB too hard (e.g., to leave the OB by a pocket if you can't or don't want to pocket it, to increase the effective size of the pocket, or with some one-pocket shots), while still maximizing draw (e.g., to achieve position for the next shot or to play a safety).
2. ... you want to keep the draw angle as narrow as possible when there is a cut angle (e.g., to avoid a ball or a pocket, or to get straight up or down the table better).

Here are the results of the analysis:

1. Generally, to get more spin at contact with the OB, you must hit the CB harder and lower. However, as you approach the miscue limit, you get a smaller gain in spin. And for longer drag distance shots, the amount of spin actually decreases as you approach the miscue limit (see Graphs A and I). See TP B.8 (Download) for more info and results.
2. More tip offset results in a greater spin-to-speed ratio at OB contact (except for long drag shots, especially if conditions are "sticky" (see Graphs B and J). So to get a better spin-to-speed ratio, hit as low as you can on the CB without being at too high a risk of miscuing.

The graphs mentioned above can be found in TP B.9 (Download). For more info and illustrations, see "Draw Shot Physics - Part III: spin ratio" (Download) (BD, June, 2009).

TP B.10 - Draw shot cue elevation effects (Download), looks at the effects of cue elevation. Here are the conclusions from the analysis:

1. Elevating the cue reduces the amount of CB spin at OB contact, resulting in less draw distance (see TP B.8 (Download) for more info). The loss in spin is small for small cue elevations, but increases with more elevation (for a given cue speed and tip offset).
2. Modest cue elevations (about 0-15 degrees) reduce the spin-to-speed ratio of the CB at OB contact, resulting in "slower" draw (see TP B.9 (Download) for more info).
3. As you increase cue elevation above about 20 degrees, the spin-to-forward-speed ratio increases, allowing for "quicker" draw (see TP B.9 (Download) for more info). An extreme example is a highly elevated masse draw (pique') shot, where you create lots of backspin with very little forward speed.

Sometimes cue elevation is required to clear over an obstacle ball, or to prevent a double hit when there is a small gap between the CB and OB. And as noted above, with larger cue elevations, better "quick draw" action can result. However, for maximum draw distance, a level cue (or as close to level as possible) appears to be best. For more info, illustrations, and examples, see "Draw Shot Physics - Part IV: cue elevation effects" (Download) (BD, July, 2009).

The math and physics is fairly involved, but here's the basic concept:
With an elevated cue, the CB doesn't lose any speed or spin while it is airborne (between the bounces); however, more speed and spin is lost during the bounces (including the first bounce off the tip, based on HSV B.44 (YouTube)) than with a near-level-cue drag shot.

Power draw
How do you achieve good power draw?
First of all, make sure you follow all of the advice concerning good draw shot technique in this section. Also, many important principles involving power draw can be found in the physics-based advice in this section. More general advice and video demonstrations can be found in the elbow drop and pendulum stroke in the "stroke" section.

Here's a good video demonstration from Disc I of The Video Encyclopedia of Pool Shots: (external web-link)

For more information, see: "Draw Shot Physics - Part I: basics" (Download) (BD, April, 2009) and “How High or Low Should You Hit the Cue Ball?” (Download) (BD, September, 2011).

Here's a power-draw shot by Mike Massey:

Quick draw
How do you get the cue ball to draw more quickly with a cut shot?
To have the cue ball draw back more quickly at a shorter angle and less tangent-line motion with a cut shot, you want to have as much backspin as possible with as little forward speed as possible. The result is called quick draw. To get the largest effect, you need to elevate the cue (see TP B.9 (Download) for more info). Cue elevation also allows one to create less object motion for a given amount of cue ball draw. For examples and more info, see "Draw Shot Physics - Part III: spin ratio" (Download) (BD, June, 2009) and "Draw Shot Physics - Part IV: cue elevation effects" (Download) (BD, July, 2009). Here are some related videos: (YouTube videos)

• NV B.25 – Using draw and side spin to beat a scratch in a side pocket
• NV B.26 – Draw shots near a rail
• NV B.47 – Draw shot off a rail requiring slower speed for position
• HSV B.23 – Cue ball path speed, spin, and cue elevation effects
• NV B.45 – Cue ball path speed effects

For more info on cue elevation effects, see cue elevation effects in this section.

Trisect aiming system
Is there a rule for predicting CB direction for a draw shot similar to the 90-degree rule for a stun shot and the 30-degree rule for a rolling CB shot?
Yes. It is called the trisect system, which applies to a"good action" draw shot for cut angles smaller than about 40 degrees (i.e., ball-hit fraction greater than about 3/8). You can use a modified version of the Dr. Dave peace-sign technique to predict the cue ball direction. Here's a good video demonstration from Disc I of The Video Encyclopedia of Pool Shots (Download):
YouTube video: Trisect aiming system

Here's another video, from Disc II of the Billiard University (BU) Instructional DVD series(Download), that shows how you can use the trisect system effectively when you have ball in hand:
YouTube video: Trisect aiming system II

For more information and demonstrations, see:
"Draw Shot Primer - Part III: using the trisect system" (Download) (BD, March, 2006)
"Draw Shot Cue Ball Directions" (Download) (BD, December, 2011)
where the CB goes for different cases("position" section)

Here's a convenient 1-page trisect system resource page (Download) summarizing the important concepts.
See also: shot speed effects in "position" section.

For more info, visit billiards.colostate.edu

Drills and Games

Drills and Games in Pool and Billiards
... useful drills and games for helping you improve at pool.

(external web-link) for lots of drills and practice shots:
see the Video Encyclopedia of Pool Practice (VEPP)

American rotation
What is American rotation?
American rotation is a 15-ball game developed by Joe Tucker (external web-link) similar to 9-ball and 10-ball, but with slightly different rules. Instead of the game being won by pocketing the highest numbered ball, it is a points game where each ball pocketed earns a player points. Balls 1 through 10 are worth 1 point each and balls 11 through 15 are worth 2 points each. The game is played to a pre-set number of points (e.g., 150). The first person to reach the target number of points wins the game. Like all rotation games, the lowest-numbered ball on the table must always be struck first, and you continue shooting after pocketing a ball with a legal shot. Unlike 9-ball, slop doesn't count. All shots must be called (unless they are obvious). If a shot is missed, the opponent has the option to shoot or have the current shooter remain at the table (e.g., if the cue ball is left in a bad place after a missed shot). If you don't want to attempt to pocket a ball, you also have to option to call and play a safety.

The first break is decided by a lag shot. A full rack of 15 balls is used on every break. After the first break, there is an option to shoot, play safe, or push out as in 9-ball. After every subsequent break, the shooter takes ball in hand after the break. Whoever pockets the last ball on the table breaks another full rack of 15 balls with ball-in-hand behind the head string. This continues until a player reaches the target number of total points.

In the event that your opponent fouls on three consecutive shots, you get a free shot (i.e., if you miss, you get an extra turn before your opponent returns to the table). This free shot only applies to the current rack (i.e., it doesn't carry over to the next rack of balls).

Billiard University (BU) playing-ability exams
What are the BU exams, and how do I rate myself and earn a diploma?
The Billiard University (BU) exams (external web-link) offer a collection of well-designed drills that assesses a wide range of pool skills. More information can be found on the BU rating systems on "rating" section.

Bonus Ball
What is Bonus Ball?
Bonus Ball is a pool game developed by Larry Chiborakthat is a combination of 8-ball, 9-ball, snooker, one-pocket, and straight pool.Here's a concise summary of the rules from the WPBL website:
Bonus Ball is played with nine billiard balls: four purple, four orange, and one black Bonus Ball. The objective of the game is to reach 30 points by pocketing balls. Each legally pocketed purple ball is worth one point, orange two points, and the Bonus Ball three points. Pocketing all three in order is called a "sequence". A player will continue their visit at the table until they fail to legally pocket a ball, or commit a foul. If a player fails to pocket the Bonus Ball on their turn, during their next visit to the table they will restart the sequence at purple. After the final orange ball is pocketed leaving only the Bonus Ball, the purple and orange balls are re-racked, and the active player must perform a re-break. The game is played until a player reaches 30 points or the 15 minute game clock expires. Failure to reach 30 points within regulation time will result in a shootout.

And here's a 60-point run (in a shoot-out final) by Thorston Hohman.(YouTube)

Bank shot drills
What are some good drills for practicing bank shots?
Here are some examples from Disc IV of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Bank shot drills(YouTube)
Bank shot challenge drills(YouTube)

More information can be found in “VEPP – Part XI: Bank Shots,” (Download) (BD, February, 2013).

Carom shot drills
What are some good drills for practicing carom and kiss shots?
Here are some examples from Disc V of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)

Colin's potting drill
What is a good drill for measuring and monitoring a player's aiming and shot making ability?
Colin Colenso came up with a useful potting drill to assess shot making ability for a wide range of shots over various cut angles, distances, and directions. It consists of 80 shots, and takes a while to complete (e.g., 30-50 minutes), but it is time well spent. More info can be found below.

Here is a useful printable file containing the diagram, along with scoring sheets. (Download)

from Colin Colenso:
Here is a test I devised to see how well you pot.

There are 16 pot challenges (see diagram below). They challenge your potting from both sides of the table. Perform each pot 5 times and make a total out of 80. Scratching is ok, slop is not ok.
If you're not patient just do 2 of each pot and multiply your total by 2.5.

Rating System:

• Under 20: Bad eyes, possibly drunk, needs a doctor, doesn't know what the chalk is for, should try bowling.
• 20-29: Beginner / Casual Player
• 30-44: C
• 45-59: B
• 60-69: A
• 70-79: Pro Level Potter - Not necessarily pro level player of course
• 80: PR#@K - Please take up bowling so we can have a chance

from dr_dave (from AZB post by theUBC (external forum link)):
Here's another useful shot-making drill from Ekkes that also include practice with stun, follow, and draw:
video demonstration by Ekkes (YouTube)

Custom drills
How and why should I create and practice drills customized to my individual needs?
Here are some examples from Disc V of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Custom pool drills(YouTube)
Custom pool drills II(YouTube)

For more information, see VEPP – Part XIV: Custom Drills (Download) (BD, May, 2013).

Drill resources
Where can I find useful drills to help my game?
Many drills from various sources can be found here:
Instructor and Students Resources (external web-link)

The Video Encyclopedia of Pool Practice (VEPP) (external web-link) is also an excellent drill and pool workout resource.

8-ball bowling and 10-ball bowlliards
from WoodMonkey:
(1) Set up rack and break.
(2) After break, choose stripes or solids and shoot until you miss (calling all shots). Then shoot the other group until you miss. (One run on each).
(3) That makes one frame (of ten). Here's how to score:

a. If you don't run out, score just one point per ball made (maximum would be 14, all 7 of each group.)
b. If you do run out, score as follows: If you made a ball on the break, and run out first group, score 30. If you made a ball on the break, and run out second group, score 25. If you don't make a ball on the break, and run out first group, score 20. If you don't make a ball on the break, and run out second group, score 15.
c. If you foul at any time in any way during a run, score 0 for that group. (If you scratch on the first group, take ball in hand for second group.) If you scratch on the break, shoot from kitchen but take 5 off your score for the frame.
d. Safety Play: I also include a safety play rule so I have an excuse to practice safety play. My rule is that if I call a safety, I succeed if the ball lands such that my opponent would have to kick to hit one of his balls. If I do this, I continue whatever run I'm on with ball in hand.

As with bowling, the maximum possible score is 300.

from marek:
I know a game named "bowlliards". It is played with ten balls and its played like this: you break them and you have ball in hand. If you run them all in one inning its a strike, if you make a mistake you have second inning and if you run them in the second inning its a spare. Simple as that.

Equal Offense
What is Equal Offense?
Equal Offense is a non-head-to-head game based on straight pool. The goal is to score as many points as you can in 10 innings at the table. Each inning begins with an open break shot. Any balls pocketed are spotted. The maximum allowed score for each inning is 20, for a maximum possible score of 200. As with straight pool, after pocketing the 14th ball, you must re-rack the 14 balls (with the lead ball missing) and attempt to break the rack while pocketing the 15th ball that remains on the table.

After each inning-starting break, you start with ball in hand in the kitchen. As in straight pool, it is important to think about balls that can serve as the break shot ball in case we run the other 14.

Fargo rating drill
What is the Fargo rating drill and how does it work?
Fargo is an excellent practice and rating drill developed by Mike Page. More info can be found here:

• Fargo video description and demonstration (YouTube)
• Fargo rules summary and score sheet (Download)

Note that the "Fargo rating drill" is different from the Fargo player rating and handicapping system(rating section).

Hopkins Q Skills
What is Hopkins Q Skills?
Hopkins Q Skills is an excellent rating drill developed by Allen Hopkins, which is a combination of straight pool and rotation. More info can be found here. (external web-link)

Jump shot drills
What are some good drills for practicing jump shots?
Here are some examples from Disc IV of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Pool and billiards jump shot drills(YouTube)

For more info, see: VEPP – Part XII: Jump Shots (Download) (BD, March, 2013).

Kick shot drills
What are some good drills for practicing kick shots?
Here are some examples from Disc IV of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Pool and billiards kick shot drills(YouTube)

Here's another useful kick shot drill, from Disc III of the Billiard University (BU) Instructional DVD series: (external web-link)
​Kick shot aiming system drills(YouTube)

Line-of-balls drill
How does the line-of-balls drill work and how can it help me improve cue ball control and position play?
Here's a description and demonstration from Disc II of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Line of balls drills(YouTube)

See “VEPP - Part VI: Line-of-Balls Drill,” (Download) (BD, September, 2012) and "Billiard University (BU) - Part II: Skills Exam,"(Download) (BD, September, 2013) for more information.

MOFUDAT (center-ball stroke drill)
What is a good drill for testing my stroke and how well I can hit the center line of the cue ball?
See "Fundamentals - Part I: MOFUDAT" (Download) (BD, September, 2008). It discusses the MOFUDAT drill (Download) (The "MOst Famous and Useful Drill of All Time"). A demonstration of the drill, along with additional useful information, can be found in these videos:
Drills I(YouTube)
MOFUDAT drill(YouTube)

Here's another good stroke drill, using two golf tees:
Stroke training drill(YouTube)

See also:
finding the center of the CB in "vision" section
fundamentals "best practices" check-sheet (Download)
stroke "best-practices" in "stroke" section

Position control drills
What useful drills for practicing cue ball control and position play?
Many can be found on Disc II of the Video Encyclopedia of Pool Practice (VEPP). (external web-link) Here are a few examples:
Cue ball control drill(YouTube)
Pattern learning drill(YouTube)
8 ball drill(YouTube)

Here are some additional useful position control drills from the Billiard University (BU) Instructional Series: (external web-link).
Stun shot drill(YouTube)
Cue ball control target pool drill(YouTube)

Progressive practice
What is progressive practice?
Progressive practice is an approach to drills where the difficulty level matches the players ability. The drill also results in a rating score that can be tracked over time to monitor improvement. More info can be found in "VEPP – Part II: Progressive Practice, and Draw Drills," (Download) (BD, May, 2012), in Bob Jewett's handout (Download), and in Mike Pages's video. (YouTube)

Here's an example progressive-practice drill from Disc I of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Progressive draw shot drill(YouTube)

and here are some fun draw shot challenge drills from the same DVD:
Back spin draw shot drills(YouTube)

Safety drills
What are some good drills for practicing defensive safety play?
Here are some examples from Disc III of the Video Encyclopedia of Pool Practice (VEPP): (Download)
Safety drills(YouTube)
​Safety drills part 2(YouTube)

For more information, see: “VEPP – Part IX: Safety Drills,” (Download) (BD, December, 2012).
Here are some fun challenge games and drills from Disc V of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Safety challenge drills(YouTube)

Here's another safety drill from the Billiard University (BU) Instructional Series: (external web-link)
Safety drills(YouTube)

For more info, see “Billiard University (BU) - Part VIII: Safeties”(Download) (BD, March, 2014).

Target practice drills
How do target practice drills work, and how can they help me with cue ball control and position control?
Here's an introduction and example from Disc II of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)
Target practice drills(YouTube)
See "VEPP – Part IV: Target Practice Card Trick," (Download) (BD, July, 2012) for more information.

Here's another useful position-control target practice drill from the Billiard University (BU) Instructional Series: (external web-link)
Cue ball control target pool drill(YouTube)

3-ball drill
This is probably one of the simplest, most common, and most useful drills for developing good offensive skills. Here's how it works:

1. Randomly throw out three balls (e.g., the 1-ball, 2-ball, and 3-ball) on the table. If a ball drops, randomly throw it back on the table.
2. Take cue ball in hand and pocket the three balls in rotation (i.e., in numerical order).
3. Keep track of how many 3-ball patterns you run (e.g., out of 20), and see if you improve over time.

If you are very successful with three balls (e.g., 18-20 runs out of 20 patterns), increase the number of balls to four and then more. If you can progress to 15 balls and make a high percentage of the patterns, then you can join the pro tour.

Wagon wheel drills
What are wagon wheel drills and how can they help me with cue ball control and position control?
Here's an introduction and example from Disc II of the Video Encyclopedia of Pool Practice (VEPP):(external web-link)

See "VEPP - Part III: Wagon Wheel Drills," (Download) (BD, June, 2012) for more information.

Why do drills?
What is the value of doing drills, and how can it be better than practicing through normal play?
from lfigueroa:
I believe there are several different ways to look at drills.

First off, I think you can look at drills as an end in themselves. Work the drills and learn variations on a standard -- maybe like playing "Chop Sticks" on a piano. A drill can show you how minor riffs can produce divergent outcomes -- selection of speed and spin all dramatically changing what the balls will do on any given shot -- similar but different.

Second, some people need a little structure to maintain their interest while practicing. IO W, the drill is an overt tool to help maintain focus. One guy likes the treadmill, the other likes an outdoor run. One guy can practice 9 ball or 14.1, the other likes drills, but they both want the benefits of the exercise. And for these folks, drills are a great little game of solitaire to strive and measure their performance against.

Personally, I think the most valuable way to look at drills is like a Zen koan. The drill is just a vehicle to get you inside your game, your mechanics, your stroke, your mind. This is also the toughest way to workout. You are not only working on the aggregate shots and required positional plays of the drill, you are also seeking to achieve a mental state wherein you can become introspective about your choices, mechanics, and stroke. There's the real payoff.

wax on
wax off

from Neil:
Doing fundamental drills will "groove" your stroke. Without a repeatable, straight stroke, all else is nothing more than a crap shoot.
Doing pocketing drills will increase your confidence and ability in making balls. It will also show you which shots are low percentage for you.

Doing pocketing drills combined with positional drills will increase your confidence and abilities in pocketing and positional play.
Playing the ghost will enable you to take your individual skills and combine them. It will teach you pressure. It will teach you how shots tie in together. It will teach you the best routes to take to make things as simple as possible. 

Doing drills will enable you to set up the same shot, and see exactly where you had a problem with it. Is it a shot that you feel you should make most of the time, but in reality you actually make less than 50% and didn't even realize it? 

In any case, drills, or playing the ghost, will do you little good if your goal is just to perform the drill a set number of times. The drills are to reinforce your muscles and your subconscious on how exactly to perform it. So that under pressure, you will perform as you trained. During drills, you should be paying very close attention to details. ALL the details, so you can actually learn something and improve.

To those that think drills are a waste of time- good luck with that. Don't be surprised when in 10 years you find out you aren't much better than you are now.

For more info, visit billiards.colostate.edu

English(side spin)

(external web-link) for more information:
see Chapter 4 in The Illustrated Principles of Pool and Billiards
and Disc II of the Video Encyclopedia of Pool Shots

Backhand English (BHE) and front-hand english (FHE)
How does backhand and front-hand English work?
Backhand English (BHE) and front-hand English (FHE) are aim-and-pivot methods used to adjust one's aim for squirt. For more information and illustrations, see "Squirt - Part IV: BHE, FHE, and pivot-length calibration" (Download) (BD, November, 2007). Also, here's a good overall video demonstration from Disc II of The Video Encyclopedia of Pool Shots: (external web-link)
Back hand English(YouTube)

Here are some other more detailed videos on the topic:

• NV A.19 - Colin Colenso's back-hand-English saga (for squirt compensation) (YouTube)
• NV B.24 - Joe Tucker's squirt, swerve, and BHE/FHE combo (part 1) (YouTube)
• NV B.24 - Joe Tucker's squirt, swerve, and BHE/FHE combo (part 2) (YouTube)
• NV B.24 - Joe Tucker's squirt, swerve, and BHE/FHE combo (part 3) (YouTube)

This video shows the effects of bridge length and the amount of squirt of the shaft:
NV B.58 - Mike Page's BHE pivot length demonstration (YouTube)

When using BHE, the bridge length must correspond to the pivot length of the cue, unless you are also compensating for swerve and/or throw.

See also: aim compensation for squirt, swerve, and throw in "aiming" section(includes more video demonstrations).

from Patrick Johnson:
BHE = back hand English = setting up for a center ball hit then moving the grip hand (back hand) sideways to apply English and compensate for squirt/swerve at the same time. Works best with higher squirt cues where the "pivot point" is somewhere near the bridge. An approximation that must be fine-tuned by feel.

FHE = front hand English = setting up for a center ball hit then moving the bridge hand (front hand) sideways to apply English and compensate for squirt/swerve at the same time. Works best with lower squirt cues where the "pivot point" is substantially behind the bridge. An approximation that must be fine-tuned by feel.

Parallel English = a bad name ("parallel" doesn't really apply) for simply placing both hands as necessary to apply English and compensate for squirt/swerve. Works with any cue, but is done entirely by feel and can be more of a challenge for some players without the initial approximation provided by BHE or FHE.

All of these are different ways of getting your cue to the same position. Only one cue position will produce the exact shot and spin you want.

Backhand English isn't an exact science - where you place your bridge for the pivot changes from shot to shot depending on how much swerve there is in the shot (which depends on shot length, speed, amount of side spin, elevation of the cue, cloth cleanliness/age, ball cleanliness/age, even humidity). Backhand English can be a useful technique despite all these variables - it will still get you closer to the correct aim adjustment for any shot, but you'll almost invariably have to make some small additional aim adjustment "by feel".

And here's the kicker: it may or may not be a good thing to know about the "by feel" part of backhand English. Most backhand English users believe (or pretend to believe) that it's an exact adjustment for every shot, which allows their subconscious to make the final adjustment without being confused by "too much thinking". Colin Colenso, on the other hand, makes all the adjustments consciously, even mathematically [for more info, see: aim compensation in "aiming" section for squirt, swerve, and throw]. You'll have to decide how to do it for yourself.

Personally, I'm somewhere between the two extremes of "totally by feel" and "Colin Colenso total consciousness". I try to think about all the variables as I'm lining up the shot, to be sure my subconscious has all the data it needs, and then I try to let that all go just before I shoot, getting out of the way of my subconscious for the final aim and stroke refinements

from dr_dave:
I'm with you on this one. I firmly believe in having a complete understanding of all of the effects, to help guide the subconscious. Even "aiming by feel" relies on subconscious understanding, IMO. I like using BHE as a starting point, especially for short and/or fast shots with a near-level cue; but I also use knowledge-based and experience-based "feel" to make adjustments to account for shot speed, shot distance, ball/cloth conditions, and cue elevation (although, I try to avoid English like the plague when cue elevation is required ... unless swerve or masse are the only or best shot options).

from Jal:
... Object balls ... are ... 'thrown' by friction with the cue ball during the collision in a direction they normally wouldn't go if you look at the geometry alone. This effect is small when the cue ball has a lot of topspin or backspin on it as it arrives at the object ball, and can generally be ignored in these cases. If the cue ball doesn't have a lot of topspin or backspin, the throw effect is greater and you'll often enough have to compensate for it. Most players learn to do this subconsciously, but it doesn't hurt to be aware of it.

Speed and distance affect how much the 'cue ball' swerves on the way to the object ball. And generally speaking (there are exceptions), speed affects how much the object ball is thrown off its geometrically ideal direction during the collision. Higher speeds actually reduce friction between the balls.

I think an easy way to remember how bridge length adjustments affect the shot when using the backhand pivot method to apply outside English (right side spin when hitting the object ball on its right side, i.e, cutting it to the left), is that with a typical cut shot, moving your bridge hand back will result in a fuller hit on the object ball, i.e., more (exposed) shaft = more object ball.

The above affects the initial direction of the cue ball as it leaves the tip. This is called "squirt", or "deflection" by some. As far as the curved path the cueball subsequently follows (swerve), striking high on the cue ball (in addition to the applied English) will generally result in more effective swerve (sideways displacement of the cue ball as it reaches the object ball), while striking low will produce less. This is for shots with only a modest distance separating the balls. The opposite can be true with large distances. (Striking low produces more swerve overall, but it happens much more gradually. Thus the term "effective swerve.")

Combining these to sort of auto-compensate when applying outside English using the backhand pivot method then, striking high on the cue ball = more exposed shaft when pivoting, low = less. And since greater shot speed reduces effective swerve but doesn't affect squirt (practically speaking), greater speed = less exposed shaft, less shot speed = more. Unfortunately, the latter is an inverse relationship, which isn't as neat and as easy to remember as the other ones. I'll leave it to you to work out these relations for inside English (left side spin when cutting the object ball to the left, i.e., still hitting the object ball on right side).

As you probably realize, these details (and others) are maybe good to be consciously aware of while developing a feel during practice. But the end goal is for all of this to become second nature.

Inside English
Why do some people like to use inside English, even on shots where it is not required for position?
First of all, the type of English is usually dictated by cue ball position requirements for the next shot, so inside English will not always be the right choice. Otherwise, here are some possible reasons to favor inside English (IE) when other English is not required (or when no English is required):

• Some people tend to undercut shots by aiming fuller than the shot requires, and inside English will create squirt that increase the resulting cut angle slightly (although, spin-induced throw will tend to counteract this some).
• A small amount of IE can counteract the effects of cut-induced spin on the cue ball, possibly resulting in a more natural and predictable rebound angle off a cushion.
• IE increases throw at small cut angles, but actually reduces the amount of throw at larger cut angles.
• The amount of throw with IE can be much more consistent than with outside English (OE) if the amount of English varies a little. In other words, the amount of throw varies more with tip placement for OE vs. IE. This might explain why some people prefer using IE on cut shots ... because they can better anticipate and adjust for the amount of throw.
• The least amount of throw, and the most throw consistency, occurs with fast IE shots.

For more information, see "Throw - Part VII: CIT/SIT combo" (Download) (BD, February, 2007),

Why does IE increase throw at small cut angles and decrease throw at larger cut angles?
Let's start with a very small cut angle to the right, but almost straight. With no side spin, the amount of throw will be very small and to the left slightly. With inside (right) side spin, the OB will throw to the left a lot more; and with outside (left) side spin, the CB will throw to the right. So in this case (a small cut angle), inside English obviously increases throw.

With larger cut angles, outside English can create throw either right or left based on whether the amount of English is greater than or less than the "gearing" amount. The following video demonstrates this effect:

HSV B.33 - Outside English gearing, and cut and spin-induced throw (YouTube). Inside English always throws the OB in the same direction because the spin is in the CIT direction. However, CIT and SIT don't add like some people might think. The following article provides explanations, illustrations, and examples:"Throw - Part VII: CIT/SIT combo" (Download) (BD, February, 2007)At small cut angles and small amounts of side spin, the CB and OB sort of stick together during contact. However, at larger cut angles and/or with lots of inside English, the CB is sliding against the OB during contact. Friction (and therefore throw) is less when the sliding speed is greater. That's why throw is actually less when you add inside with a larger cut angle, because spin increases the sliding speed during contact.

The following video demonstrates most of the important throw effects, showing how throw (CIT or SIT) varies with angle, speed, and the amount and direction of spin:
NV B.86 - Cut-induced throw (CIT) and spin-induced throw (SIT), from VEPS IV (YouTube)

See the following two videos that study this effect:

• NV B.25 - Using draw and side spin to beat a scratch in a side pocket, with Tom Ross
• NV B.31 - Using inside English and follow to beat a scratch and get down-table position

Also see the outside-English CB hold in "throw" section.

from Colin Colenso:
Inside English is often useful in taking the CB 2 or 3 rails. Often in these situations it heads for open space into the middle of the table. With a little practice this is quite predictable and leaves a player better next shot options.

For the draw with inside they may be doing this to check (hold) the CB angle off the rail. It may allow them to hit the shot a bit firmer without risking losing the CB, and by hitting it a bit harder, they avoid the risk of leaving whitey too close to the rail.

Also, inside can be very useful in getting the CB down table from say a 3/4 ball shot down the long rail.

Inside has similar throw to rolling follow so long as you don't play it too soft or from too straight on. Advanced players often utilize it. Intermediate players seem to love their OE, whereas advanced players are often weary of it, other than using a touch to gear away the throw, particularly on soft stun shots.

Why are inside-English shots more difficult for some people?
from Patrick Johnson:
It's a combination of things:
1. You use it less often (partly because you're not as good with it).
2. You use it for different (often more difficult) shots.
3. You use different spin with it (usually high vs. usually center or low).
4. You hit it at a different speed (usually harder).
5. It's less self-correcting.

Pay attention to these things while practicing inside and outside shots and you'll get better at inside pretty quickly.

A specific suggestion: pay attention to exactly where your stick is pointing on each shot compared with the CB/OB contact points - as you make and miss shots it will help you see the exact differences in how to aim them (it also helps generally to build accurate "shot memory").

Maximum English
How can I get more English on the cue ball?
In general, to get maximum English, prepare and chalk a good tip, and hit the cue ball as far left or right of center as you can without miscuing. A striped ball can useful for practice because the width of the stripe is usually half the ball's diameter, and the edges of the stripe border the typical miscue limit (at half the ball's radius from center). Here's a useful illustration of maximum (100%) English:English (side spin) in Pool and Billiards
... how to aim and compensate for various effects when using side spin (English) in pool.​

For more information, see:

• "Draw Shot Primer - Part VII: tips of English" (Download) (BD, July, 2006)
• "Coriolis was brilliant ... but he didn't have a high-speed camera - Part IV: maximum cue tip offset" (Download) (BD, October, 2005)

Maximum tip-offset considerations also apply to follow and draw shots. See “How High or Low Should You Hit the Cue Ball?” (Download) (BD, September, 2011) for more info.

Now, to achieve the most effect from side spin (i.e., get the most rebound angle change off a cushion), you want to use a drag shot where you start the CB off with backspin, and the backspin wears off on the way to the cushion. The problem with hitting below center is that you must decrease the amount of side spin (tip offset) a little. However, because the drag action slows the cue ball while retaining most of the side spin, the rebound angle will be larger. For more info, see drag follow in "follow" section.

Some people think low-squirt shafts or tip type/brand or other things can help you get significantly more spin on the CB, but this is not the case. For more info see:

• getting more spin with low-squirt cue
• miscue limit

from Jal:
Side spin (English) is used on the majority of shots to either control how the cue ball comes off a cushion, or to reduce object ball throw (with outside English). In both cases, it is the amount of spin relative to the speed of the cue ball that is important - the spin/speed ratio. This is governed nearly totally by tip offset, ie, how far from center tip contact is made. Cue speed and weight have a very slight effect. The heavier and faster the cue, the greater the spin/speed ratio (very slightly).

The factors that govern absolute spin rate, as with force follow and draw shots, have been mentioned (tip offset and cue speed), but just to add this. For any particular player, there is an optimal cue weight, one that produces the most spin, for each particular offset. No one cue will work equally well at all offsets for that player. But the good news is that over a rather broad range of cue weights, there is very little difference between them as far as cueball response. (The reason for this has to do with with the inertia of the player's arm.) Nevertheless, as a general rule, a heavier cue is more efficient at center ball, while a lighter one is more efficient away from center ball (in theory).

I would think that harder tips would be more efficient than softer ones, but some tests done by another poster here, Mike Page, suggest that this might not be the case, that they may be about the same. This is a part of cue efficiency as a whole. I suspect that there is very little difference between the "best' and "worst" cues as far as overall efficiency is concerned.

In brief, the principle factors (and virtually the only factors) are tip offset for spin/speed ratio, and tip offset plus cue speed for absolute spin rate. Having a well-chalked tip in good condition is important too, of course, as it determines how far from center you can hit.

from dr_dave:
Excellent summary!
For people who use "tips of English," tip shape can also affect the amount of spin they apply. See "Squirt - Part VI: tip shape" (Download) (BD, January, 2008) article for illustrations and explanations.
For people who want to see the math and physics behind many of Jal's statements above, see TP A.30. (Download)

Outside English
Should I use outside English to reduce the effects of throw (i.e., "spin the ball in")?
If the exact amount of outside English (OE) (called "gearing" OE) is used for a given cut angle, the will be no throw. Here's a good video demonstration of the effect:

and here are some others:

• NV B.86 - Cut-induced throw (CIT) and spin-induced throw (SIT), from VEPS IV (YouTube)
• HSV A.142 - Vernon Elliott cross-side bank with chalk on the object ball to increase throw and spin transfer (YouTube)
• HSV B.30 - Cut-induced and spin-induced throw and spin transfer (YouTube)

Throw can vary with cut angle, speed, vertical plane spin, and ball conditions, sometimes resulting in an excessive and unanticipatable amount of throw, called "cling." So it makes sense to try to eliminate all of these uncertainties if possible. But it can be difficult to have a feel for the exact amount of OE to use for different shots; although, this feel can probably be developed fairly easily. As long as one is just a little off with the amount of OE, the amount of throw could still be small enough to be a non-factor. If you want more information, illustrations, and examples of everything mentioned in this paragraph, see the following instructional articles: (Downloads)
"Throw - Part III: follow and draw effects" (BD, October, 2006).
"Throw - Part IV: spin-induced throw" (BD, November, 2006).
"Throw - Part V: SIT speed effects" (BD, December, 2006).
"Throw - Part VI: inside/outside english" (BD, January, 2007).
"Throw - Part VII: CIT/SIT combo" (BD, February, 2007).

Diagram 2 in "Throw - Part VI: inside/outside English" (Download) (BD, January, 2007) shows how the amount of English required for "gearing" varies with cut angle. Below is an illustration of an easy way to visualize how much tip offset is required to create a gearing amount of outside English (see TP A.26 (Download) for the derivation). The technique is called the 40% rule.

Using gearing outside English to eliminate throw as a variable is a good thing (when outside English is an acceptable choice), but the problem is that English also introduces squirt and swerve. Now, if the cue stick is as horizontal as possible (i.e., not elevated), and firm speed is used, swerve won't be much of a factor (but it can be in many pool shots). Concerning squirt, a low-squirt cue can help minimize the effect, and backhand English (or front-hand English) techniques can be used to help compensate. However, for many shots, squirt and swerve effects might require significant compensation. Many factors and effects need to be considered when using English, per the list available here: English effects in this section.

If cling is not much of a concern, and a player has a good feel for throw effects, maybe throw compensation (with aim adjustment) could be more straightforward than squirt/swerve/gearing OE compensation.

If cling is a concern (e.g., if the balls are old, worn, and very dirty with chalk smudges; or if you are pro, where cling on one shot can mean the difference in a match), OE might be appropriate for trying to eliminate throw and possible cling; but you need to be able to judge the required amount of English for all cut angles and be good at judging and compensating for squirt and swerve.

A problem with trying to eliminate throw with gearing OE is that the amount of throw is very sensitive to the exact amount of English when you are close to the "gearing" amount, especially with a stun shot. Therefore, the amount (and direction) of throw can vary quite a bit with small misjudgments and inaccurate application of the gearing amount of English. As demonstrated in HSV B.33(YouTube), if you have more than the "gearing" amount, the the OB will throw in the direction of the spin (SIT: spin-induced throw); and if you have less than the "gearing" amount, the OB will throw in the cut direction (CIT: cut-induced throw). An argument can actually be made that using inside English is a better approach for dealing with throw. For information about how "gearing" English changes with cut angle, and for lots of illustrated examples, see "Throw - Part VI: inside/outside English" (Download) (BD, January, 2007).

Also, OE might not be appropriate for a given shot, based on position play requirements (e.g., to get position on the next shot, inside or no english might be required instead). So it seems one needs to able to compensate for throw anyway to be able to have a full arsenal of shots. Now, if you don't need English for position on a particular shot, this is a moot point.

Outside English can certainly be appropriate when trying to hold the cue ball (sometimes). For more info, see: holding the cue ball in "throw" section.

One thing is for sure: OE (or any English) is probably not the best choice with long-distance thin cuts, where aiming precision is key. Here, a center-ball hit will result in the best accuracy and consistency.

from Bob_Jewett:
It's usually impossible to plan a run-out using only outside English, as has already been mentioned. You might have "English freedom" on 20% of your shots. If you're not going to hit a cushion or just barely bounce off a cushion, your side spin doesn't matter, so you are free to use what you will. If you have very good speed control and pattern planning, you might use the cushion on less than half your shots.

The main up-side in using outside English is that it eliminates throw and skid which come from ball-ball friction at the point of contact between the cue ball and object ball. With those eliminated, you are not at the mercy of changing frictional conditions on the shot.

The problem with using this "smooth rolling across the object ball's surface" technique is that it requires a lot of skill and experience to get right. The amount of outside required depends on the cut angle, the distance to the ball, and the amount of draw/follow. As has been pointed out by Dr. Dave, Ron Shepard and others, if you get it wrong by a little the shot can go wrong by a lot.

I think the main factor is on skids. This is also called "cling" and in snooker-playing regions "kick." I think the best name for it is "bad contact." In any case, it seems to be due to chalk at the contact point of cue ball on object ball and it causes large amounts of throw. Some players don't even realize that skid exists and think that when people complain about getting a skid/kick/cling/bad contact they are just trying to make excuses. Skids can happen on maybe 1 shot in 50 to 500 depending on conditions and the sort of shots taken.

So, where is this all going? If a player just flat out misses 30% of the shots he shoots at, he's got no reason to take special, complicated precautions to avoid a 1% problem. At that level he should be working on bringing his stick straight through the middle of the cue ball with maybe a little follow or draw. Nice and smooth and not too hard. Such a player has only a dim notion of squirt, swerve and throw, and probably no knowledge of skid.

On the other hand, if you're Rempe or Sigel or Hohmann, and on a good day you miss only one time in 200 shots attempted, you can't afford to have the object ball skidding off randomly one time in 100.

So the bottom line is that whether you should try to use outside English on the fraction of shots that allow the freedom to use it may well depend on how well you play.

from Patrick Johnson:
I believe the main difference between using inside and outside spin is familiarity. We naturally use outside spin more because (1) the places we want the CB to go are more often in the outside spin direction (because we're usually shooting into a corner) and (2) we can usually hit more softly with outside to move the CB the same distance (because the natural carom angle is usually in the outside spin direction).

This built-in preference for outside spin reinforces false feelings like the "helping English" and "self correcting" myths. In fact, since throw tends to correct for squirt but throw is reduced with outside spin, you have to adjust your aim more with outside than with inside, and a shot with "gearing" English is more sensitive to small spin errors.

Rail cut shots
For general advice on how to aim and pocket rail cut shots, see Section 4.06 in The Illustrated Principles of Pool and Billiards (external web-link). Also see "VEPS GEMS - Part III: English and Position Control" (Download) (BD, March, 2010).

How can I control CB direction and still pocket the OB with a rail cut shot?
The answers can be found in the super-slow-motion video clips below, which are listed in order based on how far down-table the cue ball travels. The object ball is pocketed in all of the clips from two diamonds up from the corner pocket. (YouTube and internal videos):

• HSV A.128 - Rail cut-shot hitting the ball first, with fast speed, slight draw, outside English
• HSV A.132 - Rail cut-shot hitting the rail first, with natural (running) English
• HSV A.141 - Rail cut-shot hitting the rail first (barely), hitting the ball during initial compression, slower, with stun and lots of natural (running) English

All of these cases are also presented with graphics and narration on the HSV DVD. (external web-link)

Here are some demonstrations from Disc II of the Video Encyclopedia of Pool Shots (external web-link) that shows some examples:

Using English rail first(YouTube)
For many examples and explanations of how to judge fouls with rail cut shots, see:
Pool rules quiz(YouTube)

Is it possible to overcut an OB frozen to a rail?
Yes.
 from Patrick Johnson:
the CB contacts the rail a short distance away from the OB and moves toward the OB while in contact with the rail. Maybe it will help to show a "time lapse series" of drawings showing how the CB approaches the OB while in contact with the rail:

1. Initial contact with the rail. The CB's "equivalent straight line path" is the same as it's initial path into the rail.

2. Closer to the OB but not yet in contact with it. The CB's "equivalent straight line path" has changed, but the CB is still moving into and compressing the rail.

3. Contact with the OB. The CB's "equivalent straight line path" has changed more, but the CB is still moving into and compressing the rail.

Spin axis "flip" demonstration
When you hit a striped ball with bottom-left English, and the stripe is initially aligned with the English direction, the stripe appears to "flip" during the shot. How does this work?
The following video demonstrates and explains (with the help of high-speed video) how the spin axis changes as drag converts bottom spin to forward roll, while English persists. Here it is:

Check it out and give it a try. It's a cool visual demo.

"Spin," "slide," and "roll"
What is the difference between "sliding" and "rolling", and can a ball "roll" when it has side spin?
When a ball is sliding, drag action eventually converts bottom spin to stun and then to forward roll.

A ball starting out with pure side spin and no top or bottom spin (i.e., stun) slides at first but immediately starts to develop forward roll due to sliding friction. See the spin axis "flip" demonstration in this section for a good illustration of this. Once full roll develops, there is no longer any sliding. At that point, the ball continues to roll forward with side spin. Both the forward speed and spin gradually slow due to rolling and spin resistance.

If a ball were rolling on an inked surface, the ink trace on the ball would be a circle. If the ball is rolling with no side spin, the circle is vertical and goes around the full circumference ("great circle") of the ball. If the ball is rolling with side spin, the circle is smaller and tilted. With more side spin and/or less forward speed, the circle is smaller and more tilted. A ball with lots of spin and very little forward roll would trace a very small circle. A ball spinning in place traces a point (the smallest possible circle). Every "rolling" ball traces a circle, and as the side spin wears off, the circle size and tilt angle change.

See OB "swerve" and "turn" in "swerve" section for an explanation and demonstrations of how and why a ball rolling with side spin travels in a straight line.

from Patrick Johnson (paraphrasing Mike Page):
Imagine that there's a cylinder (like a barrel) exactly the right size so that it's just contained within the ball. The cylinder/barrel's top and bottom edges meet the ball's surface like two latitude lines drawn around a globe in the northern and southern hemispheres.

Now imagine that you've tilted the barrel and are rolling it along the table's surface like you'd roll a barrel on its edge. You can see that the axis of rotation is tilted, and the barrel's bottom edge rolls along the table in a straight line without sliding at all.

Now imagine the ball surrounding the barrel rolling along with it across the table. This is how a ball rolls across the table with side spin - no sliding, just rolling. If you were to put wet ink on the table it would mark a line around the ball at its "southern latitude" line.

The remaining wrinkle is that as the ball rolls its side spin wears off and its axis of rotation becomes more and more horizontal. To visualize this, imagine that the tilted barrel within the ball tilts more and more onto its side, and simultaneously becomes fatter and fatter and shorter and shorter, but it continues rolling on its edge (you should be able to visualize doing this with a barrel that changes this way as you roll it). Eventually, when all the side spin wears off, the fatter, shorter barrel becomes a flat disc rolling vertically on its edge. The wet ink line marked on the ball is actually a spiral that starts as a small tilted latitude and becomes a vertical "great circle" longitude when the ball is rolling normally without side spin.

Can a cue ball have more top spin than actual rolling speed?
Yes, about 25% more. For illustrations and more information, see "Coriolis was brilliant ... but he didn't have a high-speed camera - Part IV: maximum cue tip offset" (Download) (BD, October, 2005). See normal roll, maximum offset, and overspin in "follow" section for more information.

There is often much confusion and misinterpretation about the various terms related to spin and English. Here's a good summary of definitions:

• "roll" = "normal roll" = forward motion with the right amount of topspin to prevent sliding
• "sliding" = "stun" = translation with no topspin or bottom spin
• "over spin" = "extra topspin" = topspin faster than rolling rate
• "English" = "side" = side spin

Terminology and uses
What terms are used to describe different types of spin on the cue ball, and what is English used for?
English or "side" refers to side spin applied to the cue ball (CB) by hitting left or right of the cue-ball vertical center line. Proper usage suggests the term "English" is preferable to "English" for describing side spin, but "English" is also commonly used. See VEPS II - English and Position Control (external web-link) for complete descriptions, illustrations, and demonstrations of all English-related concepts and terminology with shot examples.

Here are the different names used to refer to the type of English:

The purpose for side spin is to alter the path the CB takes when it hits the rail cushions:

NV 4.25 (YouTube) demonstrates how English can be used to help with position control. An English drill (Download) can be helpful in learning to experimenting with all the factors. More drills can be found on VEPP II - Position Control and English (external web-link). English is also used with throw shots, spin transfer shots, rail cut shots, and masse shots.

English is given different names based on how it is used:

For more information on specific topics, see:

• inside English
• outside English
• squirt, swerve, and throw effects in "aiming" section
• "tips" of English

Also, the online glossary (Download) has definitions of most terms and phrases related to English.

from CaliRed:
English to me, is very simple. It is used to describe side spin. Meaning that anything hit a millimeter to the left or right of center ball, is going to be English. It will be left or right English.

Additionally, left or right English can be described with the terms, inside or outside. Inside or outside is determined by where the cue ball is, in relation to where ever it's going to hit, whether it be just a rail or a object ball. Inside can also be described as reverse and outside can be described as running. Confused? I'll summarize at the bottom of the cue ball pic.

Hopefully the picture below helps describing what I am saying.

If one was to describe Example 1. They would one of the following.... 
I hit it with high left
I hit it with top left
I hit it with left follow

Depending on the placement of the balls, they could substitute left with either inside (reverse) or outside (running) and say this.....

I hit it with high inside/outside
I hit it with top inside/outside
I hit it with inside/outside follow

Now if they wanted to be more specific, which is very helpful, they would include a common reference of measurement, "a tip" In all the examples above, if a person wanted to describe exactly what they used, they would inject the number of tips to indicate exactly where to hit the cue ball.

In the example, one could say
I hit it with 2 tips of top and 2 tips of left (or inside/outside or running or reverse)
I hit it with 2 tips of follow and 2 tips of left (or inside/outside or running or reverse)

I hit it with I hit it with 2 tips of high and 2 tips of left (or inside/outside or running or reverse)

SUMMARY:
English is only used to describe left or right of the center of the cue ball. It is NOT used to describe hitting above or below the center of the cue ball. You don't say "I hit it with top English" or "I hit it with bottom English"

Left or Right English can also be described as inside or outside English.
Inside or outside English can also be described as running or reverse English.
In MOST cases, Inside English is reverse. In MOST cases outside English is running.
When it is not, is pictured in the example below.

Inside or Reverse English means the cue ball is going to die or shorten up after it hits the rail
Outside or running English means the cue ball is going to haul ass or lengthen after it hits the rail.

Final Summary!
English is left or right, English is inside or outside, english is running or reverse.

Left can be inside or outside
Left can be running or reverse

Right can be inside or outside
Right can be running or reverse

Inside can also be described as reverse
Outside can also be describe as running

How much tip offset is required to create perfectly natural running English, where the CB rolls on the cushion with no sliding motion?
from Patrick Johnson (from AZB post (external forum-link)):

"Tips of" and percentage english
What does it mean when somebody says "one tip of English"?

"Squirt - Part VI: tip shape" (Download) (BD, January, 2008) and "Draw Shot Primer - Part VII: tips of English" (Download) (BD, July, 2006) illustrate and explain "tips" of English. "One tip" of English corresponds to shifting the cue one tip-width away from the center of the ball. Because the actual tip offset for "one tip" of English depends on both the tip size and shape, I prefer specifying the amount of English as a percentage instead (100% for maximum English at the miscue limit, 50% at half of maximum).

The illustration below, from the tip shape article (Download), illustrates the difference between "tips of English" and "percentage English:"

Some people interpret "tips of English" to actually mean "1/2 tips of English." For them, "1 tip" corresponds to shifting the cue half of the tip's width (from the center of the tip to the edge). Using this scheme, the number of "tips" for the tip size and shape in the diagram above would actually be 0 for 0%, about 3/4 (2 * 0.37) for 25%, 1 1/2 (2 * 0.75) for 50%, and almost 3 (2 * 1.40) for 100%. Below is an illustration of the two common definitions of "tips:"

Some people interpret "tips of English" to actually mean "chalk marks." Here's a photo from an AZB post by iusedtoberich (external forum-link) showing chalk marks (the round shape a chalked tip leaves on the CB after a hit):

Chalk mark size can vary with tip hardness and shape, and with shot speed, but the average size is about 5/32" or 4 mm. Maximum English is about 3 to 4 "chalk marks."

A "tip of English" is also sometimes interpreted to mean "the amount of English that creates one diamond of angle change across the table" (i.e., one "diamond of English"). Here's a photo from an AZB post by Patrick Johnson (external forum-link) illustrating this interpretation:

When to learn
When should someone start learning English (side spin)?
I don't think a person should spend much time with English until his or her fundamentals and stroke are solid. When deciding to use English seriously, a person should also start learning about all of the effects that need to be taken into consideration. For more info, see aim compensation for squirt, swerve, and throw in "aiming" section.

from Bob_Jewett:
As far as the basic knowledge part, I think it is important to discuss that before the beginner starts using side spin. I point out how the side spin can be useful but at the same time I show five major problems with using it: squirt, swerve, throw, miscues and cling/skid/kick/bad contacts, and some of the details of those problems. Most beginners do not fully understand those problems when first introduced to them, but I want them to be aware that problems exist.

For more info, visit billiards.colostate.edu

Eyes and Vision

Eyes and Vision in Pool and Billiards
... various concepts and techniques for pool shot sighting and visual alignment.

Depth perception
Is depth perception important in aiming?
Assuming you have already visualized the required impact line and ghost ball target (see NV 3.2 (YouTube)), aligning the cue stick with the aiming line direction does not require depth perception. (In fact, the parallax created by binocular vision, even with a dominant eye, can make straight-line sighting difficult.) Now, some people might adjust their aim while in their stance based on their perception of the "angle of the shot," impact line, contact point, and/or ghost ball target. In that case, depth perception might be helpful.

A low stance helps one better align the cue with the desired aiming line, without requiring too much of a shift in eye (or head) motion between the CB contact point the aiming target, while fine tuning and verifying one's aim.

For more info, see dominant eye in this section.

Interesting, the following research study showed no correlation between depth-perception ability (or other vision attributes) and pool-playing performance: "Perceptual-Motor Characteristics of Elite Performers in Aiming Sports" (Download) by Abernethy and Neal (1992).

from Qtec:
The difference between short and long bridge is that the EYES are further away from the QB when you play with a longer bridge. This means that when you focus on the QB or OB, you will see more of the shaft [ie. a longer line ] and therefore its easier to line up the cue on the line on the shot.

Dominant eye
Is one's dominant eye important in aiming?
This is debatable, and it might vary quite a bit from one person to the next. Now, head and eye position relative to the cue can be important in perceiving the desired tip contact point on the cue ball, especially if the cue tip is not close to the cue ball when lining up a shot. For illustrations and more information, see “Aim, Align, Sight - Part II: Visual Alignment” (Download) (BD, July, 2011).

3D visual perception, applied to aiming in pool, is a complicated topic that is certainly not fully understood. It is difficult to offer simple eye alignment advice (or a "formula") that will work for all people (e.g., always align your dominant eye over the cue or with the edge of the CB).

The most important advice on this issue is find the head position and sighting technique that helps create the most accurate cue tip contact point and aiming line (for a given individual). See the vision center in this section for drills and information on how to find the "vision center" head position. A person's "vision center" isn't necessarily related to which eye might be dominant or not. Regardless of where you place your head to aim and sight a shot, the most important thing is to be as consistent as possible (e.g., with a purposeful pre-shot routine), so the "sight picture" is always the same for the same type of shot.

Wikipedia has a good summaries and references dealing with dominant eye (including several methods for testing dominance) and related topics here:
ocular dominance (external web-link)
binocular vision (external web-link)

The following research study also showed no correlation between ocular dominance (or other vision attributes) and pool-playing performance: "Perceptual-Motor Characteristics of Elite Performers in Aiming Sports" (Download) by Abernethy and Neal (1992).

from RSB_FAQ:
For most people, one eye is much more dominant in seeing alignments than the other. Typically, right-handers are right-eyed, and vice versa. About 5% are "cross-dominant" (e.g., right-handed and left-eyed) and some are "ambi-ocular" (no dominant eye). To aim and sight well, it helps to locate your dominant eye directly over your cue. For cross-dominants, this may call for some adjustments in stance or neck/head angles. For ambi's, the stick will be under some spot between the eyes.

Here's how to test yourself: Hold your thumb up at arm's length, visually blocking some distant object (for example, a clock or a lamp). Don't focus on your thumb; focus on the distant object. You'll see a ghost of your thumb, since your dominant eye will be in line with both your thumb and the distant object, while your non-dominant eye will be seeing past your thumb, directly toward the distant object. With one eye seeing the thumb and the other not, you get a ghost. The ghost is centered on the distant object because your dominant eye is the one that tells you what's lined up with what.

So, when you close your non-dominant eye, the thumb becomes solid instead of ghostly, since the dominant eye is looking directly at the thumb. When you close your dominant eye, the thumb appears to jump to the side because the dominant eye (that was making the thumb line up with the distant object) is not in use.

Stroke into a mirror to see where your dominance spot is, relative to your shaft. It "should" be directly over the shaft. If it's not, but you're not having difficulty aiming or sinking balls, don't worry about it.

from henho:
... there is plenty of research on eye dominance in Medline or Pubmed, a couple of thousand articles to be exact....just one for example: A new interocular suppression technique for measuring sensory eye dominance.
Yang E, Blake R, McDonald JE.Invest Ophthalmol Vis Sci. 2009 Jul 23. PMID: 19628736 

Each eye supplies information to the brain differently. The dominant eye is used to fixate on objects. If you look at a point, the fixation of the dominant eye will fall on the center of the point while the non-dominant eye will fall slightly off-center. By comparing the difference between the images supplied by each eye the brain is able calculate depth information in a scene. The degree to which any eye is dominant varies from person to person as well.

In scenarios where estimating depth is important, the functioning of both eyes in tandem is vital. I don't recommend skiing with an eyepatch any more than driving. However, in scenarios where determining a straight line between two points is needed, using the dominant eye confers an advantage over using both eyes. When shooting a gun, you want to align the sight of the gun with a target. If you kept both eyes open while sighting down the barrel of the gun, when you looked at the sight you would see two targets, and when you focused on the target you would see two sights. In this scenario, the depth information your brain is supplying you is not helpful in aligning the target and sight, and it is easier to sight with one eye. 

Pool is an interesting scenario in that it requires good depth perception to estimate the line of sight, generally done while standing up, and in addition requires accurately lining up the cue ball with the contact point on the object ball. If you adopt a high stance and hold the cue under both eyes, you have the best depth judgment, which is needed to estimate the speed and direction of the hit. If you adopt a low stance and use your dominant eye, you have the best ability to line up the cueball and object ball. Most people go somewhere in between, where they can line up the balls while still having a general view of the table to guide the speed of their stroke. 

This seems to come into play in the nature of various cue games. In three-cushion billiards players generally adopt a more erect stance that provides a good, continuous 3-d view of the table, allowing them to accurately predict the reaction of the balls. In snooker, the accuracy requirement that smaller balls present requires players to adopt a low stance sighting down the cue. In this game moreso than in billiards, players must first estimate what will happen on the shot and determine the line of sight, then remember the layout of the table when they are down on the shot since they don't have a good view of the balls.

from JoeW (in AZB post): (external web-link)
Kahn, AZ and Crawford, JD. (2001). Ocular dominance reverses as a function of horizontal gaze angle. PubMed.
In a reach-grasp task for targets within the binocular visual field, subjects switched between left and right eye dominance depending on horizontal gaze angle. On average, ocular dominance switched at gaze angles of only 15.5 degrees off center.http://www.ncbi.nlm.nih.gov/pubmed/1...?dopt=Abstract (external web-link)

Quartley, J and Firth, AY (2004). Binocular sighting ocular dominance changes with different angles of horizontal gaze. PubMed.
A change in eye dominance occurs when viewing in the contralateral field. Differences may exist in the angle at which this occurs due to the different conditions of the various tests for ocular dominance. http://www.ncbi.nlm.nih.gov/pubmed/1...?dopt=Abstract (external web-link)

The research summarized above indicates that eye dominance can and does change as one moves into a pool shot from across the horizontal field. For some people when they move into the shot making position from the left or from the right their eye dominance shifts as they look at the sighting point.

The obvious solution to this shift in dominance is to walk into the shot from behind. While you may be looking at the shot from the side as you walk to it, you probably should not begin to sight the shot until you are in position and take a step back. This will place you on the shot line, yield a better perspective, and will give your eyes and their dominance preferences time to adjust to the visual field directly in front of you. This type of recommendation has been around for a long time and is now reinforced by the research literature.

Whether you choose to place the cue under the dominant eye or allow the brain to compensate for the dominant eye is another choice. The research literature seems to imply that shift in dominance in the lateral and contra-lateral field is not an invariant process across people: Some people experience more of a shift than others. If you have noted this shift in dominance and or a change in dominance then it is probably more important for you to step back when on the shot line and look directly in front of you prior to sighting.

A more extensive literature review on this topic would probably yield even stronger evidence as we are dealing with a physiological process offset by mental preferences. Pool instructors should seriously review this literature and it probably should be a standard recommendation based on solid research findings. While some people may not have a lateral shift in dominance the recommendation to take a step back allows one to gain a better perspective.

from Billy_Bob:
Here is more reading about the dominant eye...

Robert Byrne: "If you are having trouble pocketing balls, it may be that you aren't bending over far enough and aiming the cue like a rifle with your dominant eye."
http://www.byrne.org/pool/tips/08-1998.html (external web-link)

Eye pattern "best practices"
What is "eye pattern," and what are generally recommended "best practices" for eye pattern before and during the stroke?
"Eye pattern" refers to how you move your eyes before and during a shot.

Concerning generally recommended "best practices," see stroke technique advice in "stroke" section. In particular, see steps 1-4 in the stroke "best practices" document.(Download)

Regardless of which eye pattern you choose, it is important to have quiet eyes when aligning your cue with the desired line of aim, and during your final delivery.

Finding the center of the cue ball
What's the easiest way to ensure the cue tip is aligned with the center of the cue ball?
First, it is very important that your vision center is aligned with the cue so the tip will look centered when it is centered. It also helps to position the cue tip as close as possible to the CB in your "set" position to minimize any perspective perception problems resulting from not being aligned with your vision center. It also helps to deliberately focus on where the cue tip is relative to the CB center for a deliberate amount of time during the "set" position, with quiet eyes. It can also help some people to key off the resting point of the CB on the cloth. This can help you more accurately visualize the vertical centerline of the CB.

The drills suggested and demonstrated on the MOFUDAT, in "games and drills" section, can also be very useful to diagnose and help correct alignment and stroke flaws.

from JoeW:
I have noticed that many players begin the table aim (when they are down on the CB) by placing the tip of the cue on the table. Many players from different countries use this method as part of the aiming process and it seems there may be a reason for it. Perhaps it does help with aiming.

Apparently, when you place the stick on the table oriented through the center of the CB to the contact point, the tip is something like a pointer and you can evaluate the relative distances to either side of the CB from the center of the tip. It is easier to find center and then move relative to this place.

There is a second advantage to this method and this involves the perception of center as seen through the CB to the contact point. With the stick out of the way [there is] an unobstructed view. 

There [also] appears to be a third advantage. When the stick is initially placed on the table and the center line is sought, there is a definite tendency to place the stick on this line. The use of FHE and BHE is now relative to this line of travel for the CB to OB and it is easier to determine what needs to be done relative to a line that can be visualized as opposed to an estimated line.

Quiet eyes
What does it mean to "quiet eyes" when aiming a shooting a pool shot, and why is it helpful?
"Quiet eyes" refers to focusing on a target with still eyes for a period of time. Studies have shown that top athletes in many sport activities (e.g., golf putting and basketball free-throws) do this. When the eyes are moving and/or are not focused long enough on a well-defined target point, line, or area, performance has been shown to be not as good. Various "quiet eye" resources can be found here:

• Quiet Eyes on Google Scholar (external web-link)

Keeping your eyes "quiet" both in the set position (while looking at both the CB and at the target, separately), and during the final swing (while looking at the target) is important for consistency and accuracy. Pauses give your eyes time to settle and become quiet. In the set position, you want to alternately verify both the desired tip contact point on the CB (with quiet eyes) and the aiming line and target (with quiet eyes). And before starting your final forward swing (e.g., during the final backs wing or backs wing pause), you want to have quiet eyes and complete focus on your target point (e.g., the GB center, the OB contact point, a point on the rail, etc.).

The following research study also looked at potential correlations between vision attributes and pool-playing performance: "Perceptual-Motor Characteristics of Elite Performers in Aiming Sports" (Download) by Abernethy and Neal (1992). The study concluded that there is no correlation between various optimetric measures (dominant eye, depth perception, phoria, fixational disparity, etc.) and pool-playing performance.

Sighting
What is the "conventional wisdom" and "best practices" concerning how to sight during aiming?
See “Aim, Align, Sight - Part III: Sighting” (Download) (BD, August, 2011). It covers this topic fairly well.

Regardless of what method you choose, the most important part is to be as consistent as possible for each type of shot!!!  If you are consistent, your vision and brain will develop to "see" the correct line of aim for every shot.

By "where do you sight," I mean: where do you align your vision center, which is the head alignment that allows you to see a center-ball straight-in shot as straight, with the tip appearing to be at the center of the CB.

An obvious option is to always align your "vision center" with the center of the CB, regardless of the type of shot.  This way, you learn to see all different shots, and how they vary, from the same perspective.

Mike Page's videos on aiming and sighting present excellent background and insights on this topic.

NV B.3 - Mike Page's aiming video (part 1) (YouTube) and NV B.3 - Mike Page's aiming video (part 2) (YouTube) He points out that the only sighting that makes sense for a straight in shot is over the cue through the center of the CB.

He also points out that with a thin cut, the sighting line that makes the most sense is also along the contact-point-to-contact-point line (which will be very close to the edge-to-edge line for a really thin cut).

Then he suggests that maybe you should also sight along the contact-point-to-contact-point line for all shots in between (any cut shot). He also makes a good argument that you should probably never sight along a line that is not parallel to the aiming line (which is along the cue for a center-ball hit).

Another alternative is to always align the inside eye of the shot with the inside edges of the CB and ghost ball, so you can more clearly see the ball-hit fraction in "aiming" section (i.e., ball "overlap"). In this case, with a thin hit, you will be aligning nearly edge to edge (ETE). Some people recommend sighting exactly ETE with thin hits. An alternative here is to temporarily shift your head and close one eye to get a look at the ETE line, but then re-center your "vision center" over the cue during your final set and stroke.

Again, regardless of how you align and sight, the important thing is to align and sight the exact same way for each type of shot.  That way your brain is seeing the same picture for the same type of shot every time.

It is also very important to find your vision center and make sure you align it perfectly with the cue for straight in shots.
It is also very important to make sure the cue tip is aligned with the center of the CB when you don't intend to apply English (see finding the center of the cue ball in "aiming" section).

from Patrick Johnson:
The things you want to align for aiming (CB/OB contact points, CB/OB fractions, etc.) are rarely on the same line as your stick - they're separate lines. So when you center your vision directly over one line, the other line is necessarily off to the side a little and therefore harder to line up precisely - i.e., if you center your vision over your stick it's more difficult to be sure you're lining the contact points up precisely and if you center your vision over the contact points line it's more difficult to be sure you're lining your stick up precisely. It's a tradeoff.

So I don't think it's a given that one way is always better than the other. I'm not even sure it's necessary for a player to do it the same way every time - maybe some shots lend themselves better to one and some to the other. For instance, thin cuts and shots with lots of sidespin might lend themselves more to sighting along the contact points line, while thicker shots with less spin might be best sighted along the stick.

What's best might also change with the player - some might see the alignment better by favoring the stick while others might favor the contact points line, like how different players have different centers of vision because of eye dominance.

Is aiming a pool shot the same as aiming a rifle?
from Patrick Johnson:
Aiming a rifle and aiming a cue stick are similar, but they're not the same.

There's only one place for anybody's eye (singular) when aiming a rifle, but that doesn't mean there's only one place for everybody's eyes (plural) when aiming a cue stick or aligning balls in pool. The difference is that when aiming a rifle you're using only one eye and you can get your eye directly behind and in line with the rifle sights and the target, but when aiming a stick or balls you use both eyes and your eyes are always above the line the stick and balls are on.

You use monocular vision to aim a rifle, but binocular vision to aim in pool, and the two are very different. With binocular vision from above it isn't necessarily best to have one eye directly above the things you're trying to align - sometimes, or for some people, it's best to have the things you're trying to align somewhere between the eyes because that's where your brain assembles the twin images from your binocular vision to present the truest single image (mostly due to which eye is dominant and how strongly dominant it is).

Vision center
How can I determine the head position and eye alignment necessary for me to have the best aiming accuracy and consistency?
“Aim, Align, Sight - Part II: Visual Alignment” (Download) (BD, July, 2011) covers this topic fairly well, as does the following video from Disc I of the Video Encyclopedia of Pool Practice (VEPP): (external web-link)

Your vision center is the head and eye alignment, relative to the cue, that allows you to see a center-ball, straight-in shot as straight, with the tip appearing to be at the center of the CB. For some people, this might be with the cue under their dominant eye (if they have one). For others, it might be with the cue under their nose, or somewhere else between (or even outside of) their eyes. To be accurate and consistent with both straight-in and cut shots, you should always position your "vision center" over the desired aiming line for the shot. See shot sighting in this section for more information (and other approaches).

In general, it is best to have your head as square to the shot as possible, and with the eyes as level as possible, in the "vision center" position. For more information, see Diagram 4 and the pertinent discussion in “Aim, Align, Sight - Part II: Visual Alignment” (Download) (BD, July, 2011).

A useful technique to find your "vision center" is to set up a straight-in shot (e.g., with the CB and OB along the diagonal of the table, with the OB close to a corner pocket and the CB close to the middle of the table) with a cue shaft carefully laid down on the table centered in front of the CB and perfectly aligned with the straight line of the shot. Then position your head over the shaft close to the place and orientation your head would be while down in your stance. Then move your head left and right, without tilting or turning, until the tip position looks centered and the shaft and shot alignment look perfectly straight. This head position is your "vision center." Here's a good demonstration of this approach, using mechanical bridges (snooker "rests") to support the cue:

A good way to test your "vision center" is to use the MOFUDAT and related drills in "games and drills" section. This will test if you are aligning with the center of the CB and if you are able to consistently send the CB along a straight line. Another useful drill is the cut shot drill (F6) in Exam I of the Billiard University (BU) playing-ability tests. (external web-link) If you tend to miss shots in one direction more than the other, you might want to recheck your vision center position.

Another good drill to help you find and test your "vision center," per the first video above, is to set up a long straight-in shot into a corner pocket, marking the CB and OB positions with self-adhesive hole reinforcements (AKA, a "little white donuts"). Then hit stop shots. If the CB has no side spin after hitting the OB, and if the OB goes into the center of the pocket consistently, then you have your vision center properly aligned (and you have a good stroke). If not, then shifting your head will probably help. If the CB consistently goes to the right of target, causing the OB to go left of the pocket, your left eye is probably dominating the perception of the line of the cue. This causes you to position the cue a little to the left of center and to pivot the cue a little to the right of the desired line of aim. With your eye alignment to the left of center, you perceive the shifted and pivoted cue position as centered and straight, but it is not. If this is the case, try shifting your head to the right a little, and then try another set of stop shots. If you are consistently missing the CB target to the left instead, with the OB missing the pocket to the right, try shifting your head to the left. After you find the head alignment that results in the best accuracy (i.e., no CB spin, and OB in the center of the pocket), you will have found your vision center. When you are done, try to remember how the stance feels and/or where your nose or chin is relative to the cue (e.g., by lowering your chin to touch the cue and/or by glancing down at the cue with your eyes, keeping your head still).

When playing, you can verify that your vision center is aligned properly by touching your chin to cue if your stance is low enough to do this. Otherwise, when down in your stance, just glance down with your eyes (with the head still) to see where the cue is relative to your eyes and nose. Obviously, you want the cue in the same place as it was when you determined your "vision center" with the drills above. Regardless of what you use as your "vision center" position, the most important factor is being as consistent as possible so your brain can learn to judge the full range of shots from the same perspective.

For more information, see "VEPP – Part I: Introduction and Fundamentals," (Download) (BD, April, 2012).
Here's useful 2-page visual summary of "vision center" concepts and drills. (Download)

from Neil:
Take an extra shaft and lay it on the table pointing away from you. Get down in your stance with your cue with your bridge hand at the end of the spare shaft. Place your cue over the shaft. When you see equal parts of the shaft on each side of your cue, you then know you are seeing a straight line. That is where your head should be.

from JoeW:
Photo 1 shows the table with a line drawn from the head to the foot of the table on the center diamond. I used a dressmaker’s marking pencil (cost $1.00 at Walmart) to draw the line. I left the pencil on the table for this photo.

For a ruler I used an 8’ piece of metal wall board corner molding ($2.00 at Home Depot). Note that the line goes from one end of the table to the other.

The balls are set with the base of the One ball on the line (see Photo 2) with the center of the numeral One centered on the line. If you look over the top of the One ball you can see the other side of the ball and that the number One lines up with the white line. Go to the other end of the table and set the Three ball in the same way.

The balls are now lined up perfectly. If you hit dead center on the One, stop on the Three ball the three ball should bank off the end of the table and come back and hit the One ball – a really tough shot.

Ok so how should you aim? Well first lets get the bridge hand out of the way. To do this I reversed the table bridge and set it where the stick will line up perfectly with the center of the One ball. See Photo 3. I am holding the table bridge with my left hand and site with my eyes and the right hand. Here is the interesting part of this technique.

As I look down the shaft and line up from the One to the Three I get what I think is a good site picture. Notice where your nose is relative to the shaft of the cue stick and this is your site picture.

Now raise up a little bit and you can see over the Three ball to the head rail and you can see the white line. If everything is lined up then you are straight for your site picture. If not, something has to change.

Shooting the shot by stopping on the Three ball and watching the return from the rail will tell you if you site picture is the least bit off. This is a difficult shot and you have to be lined up perfectly. All I can tell you is --- things will change.

Please try it. By the way, you will learn if you shoot most accurately with one eye or with two eyes.

Which ball to look at last
Which ball should I focus on during the final stroke?
Best results can vary from one person to another, but it is generally recommended to focus on the object ball (or the center of the ghost ball, desired contact point, ball-hit fraction, or a point on the cloth or cushion) instead of the cue ball during the final stroke. Possible explanations or reasons include:

• By focusing on where you want the CB to go, you are more likely to send it there.
• Focusing on a more-distant target might help create a straighter delivery of the cue, and in the desired direction.
• Focusing beyond the CB might help create a more complete follow through, which is generally helpful.
• With your focus at the OB, where you want the CB to go, you get visual feedback concerning where the CB actually ended up on the OB, and you can correlate that with the result of the shot (e.g., whether you hit the ball just right, or too thick or too thin). This can help you develop and improve your aiming and visualization skills for future shots (i.e., you are improving your "shot memory").
• Most pros look at the OB last, so there must be something to it.

For shots where the cue-tip contact point is especially critical (e.g., jump shot, masse shot, shot with extreme English, when elevated over a ball, when the CB is frozen to a rail), focusing on the CB tip-contact point (instead of the OB target) during the final forward swing can be more effective for many people.

For more info, visit billiards.colostate.edu

Facts, History and Movies

Facts, History, Movies Dealing with Pool and Billiards
... various pool and billiards facts, history, and Hollywood movies.

Facts
What are some interesting billiards facts?
from 8Ball48043:
1. Billiards evolved from a lawn game similar to croquet played sometime during the 15th century in Northern Europe (probably in France).

2. The term "poolroom" now means a place where billiards is played, but in the 19th century a poolroom was a betting parlor for horse racing. Billiard tables were installed so patrons could pass the time between races. The game of billiards and the poolroom became connected in the public's mind. Today, the two terms are used interchangeably.

3. Pool is one of the safest sports in the world.

4. The dome on Monticello, Thomas Jefferson's home, conceals a billiard room. In Jefferson's day, billiards was illegal in Virginia.

5. The term "scratch", as applied to a pocketing of the cue ball, was derived from the penalty assessed for such a foul. In pool's early days, the score was often kept on a chalkboard. When a player pocketed the cue ball, his opponent "scratched" a point off the shooter's score.

6. According to research conducted a few years back, billiard champions have the highest average age of any sport, 35.6 years.

7. Tom Cruise did his own trick billiard shots for the 1986 film, The Color of Money, except for one in which he had to jump two balls to sink another. Director Martin Scorsese said he wanted to let Cruise learn the shot, but it would have taken two extra days of practice, which would have held up production and cost thousands of dollars. The shot was instead performed by professional billiards player Mike Sigel.

8. Billiards was the first sport to have a world championship (1873).

9. In 1586, the castle of Mary, Queen of Scots, was invaded and captured. The Invaders made a note of forbidding her the use of her billiard table. They then killed her, and used the covering of the table to cover her body.

10. In 1765 A.D., the first billiard room was built in England. Played there was One-Pocket, which was a table with one pocket and four balls.

11. The first coin-operated billiard table was patented in 1903. The cost of a game on the first pay-for-play table: one penny.

12. Before the invention of celluloid and other new-age plastics, billiard balls were made out of ivory. The elephants can thank their present existence on the invention of plastics. Because billiard balls had to be cut from the dead center of a tusk, the average tusk yielded only 3 to 4 balls.

13. Captain Mingaud, the inventor of the leather cue tip, was imprisoned for political reasons during the French Revolution. With the help of a fellow prisoner, he was able to have a billiard table installed in his cell. It was during his incarceration that be became obsessed with the game, that he devised and perfected his invention. His obsession became so intense, that at the end of his prison term, he actually asked for a longer sentence so that he could complete his study of the game.

14. The world's largest billiard hall was built during billiards' "Golden Age". "The Recreation", a mammoth seven-story health spa, was a bustling Detroit business in the 1920's. It featured 103 tables, 88 bowling lanes, 20 barber chairs, three manicuring stands, 14 cigar stands, a lunch counter on each floor, a restaurant that could seat 300, and an exhibition room with theater seating, that could accommodate 250 spectators.

15. The Hustler was based on a novel by Walter Tevis. The novel, however, was based on a short story he had earlier submitted to Playboy. Before "The Hustler" was released, the "Philco TV Theater" aired an episode called "Goodbye, Johnny", which bore an uncanny resemblance to the Playboy short story. In it, Cliff Robertson portrayed the cocky young hustler, making Robertson - not Newman - the original "Fast Eddie" Felson.

16. Marquetry - the art of making pictures or designs with thin slices of wood, shell or other materials - has long enhanced the beauty of tables and cues. The art form is hardly a recent development. It has been practiced in Egypt and the Orient for more than 3,000 years.

17. Wille Hoppe was truly a legendary player. Yet, his most famous match strangely had more to do with a penknife, than his unequaled wizardry of the game. In 1925, he met Robert Cannefax, the Three-Cushion champion. After several games, Cannefax, who preferred a fast cloth, asked to move the match to a different table. Hoppe, who was leading, said the cloth was just fine, and refused to allow a change. An incensed Cannefax drew a penknife and savagely cut the cloth down the center of the table. Hoppe was immediately awarded the match, and Cannefax was suspended from competition for a year. Ironically, Cannefax never played another match. He toured vaudeville for several years, and then died of meningitis in 1928.

18. Throughout most of the 1800's, the chalk used on the new leather cue tips was carbonate of lime, better known as blackboard chalk.

19. Most chalk used today is comprised of fine abrasives and does not contain a speck of chalk.

20. The Church has long been a part of billiard history. From its earliest days, the game was often denounced as a sinful, dangerous, morally corrupt activity. In 15th century France, billiards play was forbidden, by the Church, as well as the King. In early American history, actual laws were passed (thanks to religious influences), outlawing the game in many parts of the land.

21. The first 18.2 Balkline Championship was held in Paris, in 1913. It will probably be the only world championship in history ever decided by the courts. After six days of play, three contestants were tied for the first place. When a tie-breaking playoff was suggested, Maurice Vignaux, the French champion and notorious whiner when things weren't going his way, scoffed at the suggestion. He insisted the title should be awarded based on the highest overall average (which he, of course, had at the time). Vignaux refused to continue, and the matter wound up in the French courts. (Which, of course, awarded Vignaux, their countryman, the title, after a delay of more than two months).

22. No one knows exactly who, when or where the first billiard table was built. The earliest documented record of a billiard table was made in 1470. In an inventory of the possessions of King Louis XI of France, his table was said to have contained the following: a bed of stone, a cloth covering, and a hole in the middle of the playing field, into which balls could be driven.

23. What is billiard cloth made of? Amazingly, the main component of billiard cloth has remained unchanged for over 400 years. Wool was used in the 1500's, and remains the fabric of choice today. It has, of course, undergone some perfecting (and some wool/nylon blends are also produced).

24. Tables originally had flat vertical walls for rails and their only function was to keep the balls from falling off. They resembled riverbanks and even used to be called "banks". Players discovered that balls could bounce off the rails and began deliberately aiming at them. Thus a "bank shot" is one in which a ball is made to rebound from a cushion as part of the shot.

25. At times, including during the Civil War, billiard results received wider coverage than war news. Players were so renowned that cigarette cards were issued featuring them.

from Jason Janosik (via e-mail), concerning item 4 above:
It's a common misconception that billiards was illegal VA in Thomas Jefferson's day.  The truth is that the whole story is fiction. I have lived in VA my whole life and been to Monticello a few times as it is less than an hour drive from me; so when I heard this I was interested and went digging.  Virginia did levy a 50 pound tax per table in the late 1700's and it was illegal to play for betting purposes (and still is) but it was never illegal in homes.  Check out the article on Monticello's web site. (external web-link)

History
What is the history of pool and billiards?
See "history of pool and billiards" in the reference section of the instructor and student resource page. (external web-link)

Who contributed the most important historical inventions in billiards?
from jason:
CHARLES GOODYEAR - Gave us rubber and gave billiards bank shots
Discovered the process for the vulcanization of rubber. Applications of his discovery revolutionized the billiard cushion (as well as a hundred other industries). Vulcanized rubber was stable and consistent. Unlike previous rubbers, it retained its resiliency in the most searing heat and the bitterest cold. John Thurston was the first to use Goodyear's discovery in the construction of billiard cushions. The result was a consistent, reliable cushion. Bank shots, once unpredictable, became integral parts of the game. Vulcanized rubber has proven so unsurpassed, it is still used in cushions today. Charles Goodyear, sadly, profited little from his discovery. He was imprisoned for debt, his company folded, and he died a veritable pauper.

JOHN WESLEY HYATT - Inventor of the composite billiard ball
The inventor of the world's first plastic. His discovery of celluloid, in 1869, revolutionized not only the billiard ball, but countless industries worldwide. Strangely, his discovery had more to do with billiards than any plastic-related vision or enterprise. His search began as a result of a $10,000 prize, being offered for a substitute for ivory, in the composition of billiard balls.

Though his discovery was not deemed worthy of the prize, later advances in plastics led to the balls of today, and forever changed the face of the world. It can thusly be stated that the world's first plastic was actually the result of a billiard-related quest: the search for a new material, for the perfect billiard ball.

CAPTAIN MINGAUD - Invented the modern cue tip & Masse shots...honed the scientific edge of shotmaking
Invented the leather cue tip in the early 1800's. Imprisoned in France for political reasons. Was allowed the use of a billiard table inside his prison cell, and became obsessed with the game. Became a student of the physics of shotmaking, and truly transformed the cue into a scientific instrument. Revolutionized the "magic" one could impart on the cue ball, through the use of "spin" and "english."

Mingaud also discovered that by raising the cue almost vertically - in fact into the position in which the mace would be used - extraordinary spin effects could be obtained by striking a sharp downwards glancing blow to the left and right across the cue ball. This type of shot or stroke became known as the masse - French for mace. No other invention so dramatically affected "touch," control, positioning, and overall strategic play.

JOHN THURSTON - Brought table making into the Industrial Age..invented the first Slate table
English inventor and table maker. Among the first to mass-produce tables, with the onset of industrialization. Inventor of the slate table bed. Unsatisfied with the playability and warping tendency of wood, he set out in search of a new material. His discovery came in the form of slate, in 1826. Slate was cheap, readily available, and offered a far smoother surface. Its immense weight led to the construction of far sturdier tables. His innovation has truly withstood the test of time. Slate continues to be the material of choice in quality tables today.

JOHN M. BRUNSWICK - The first big name in the American Billiards Industry Swiss immigrant and woodworker. Emigrated to America in 1819. Built a billiard table factory in 1845. For nearly 150 years, Brunswick has been the most visible name in American billiards. Merged with his two largest competitors—Julius Balke, in 1873; and Phelan and Collender, in 1884. Officially became "Goliath," the largest billiard company in the world. Passed control to his family, upon his death, in 1886. For over forty years (until the Depression), the company enjoyed an incredible upward spiral of profits, growth and success. Entered (and soon monopolized) the bowling industry. Worked hard to improve billiards reputation, by teaching and donating tables to charitable groups. Drastically cut product lines during the Depression. Survived and grew again as economy improved. Sponsored thousands of tournaments over the course of the centuries. In the world of billiards, Brunswick remains the dominant name in American pool rooms and homes.

Movies
What Hollywood movies have been made featuring pool and billiards?
The most popular and successful, along with featured shots, are described and illustrated here: (Downloads)

• "Billiards on the Big Screen - The Hustler" (Billiards Digest, August, 2004).
• "Billiards on the Big Screen - The Color of Money" (Billiards Digest, September, 2004).
• "Billiards on the Big Screen - Pool Hall Junkies" (Billiards Digest, October, 2004).

For more info, visit billiards.colostate.edu

Follow

Follow Shots in Pool and Billiards
... how to hit and control a good follow shot in pool.

(external web-link) for more information:
see Section 4.03 in The Illustrated Principles of Pool and Billiards
and Disc I of the Video Encyclopedia of Pool Shots

Accuracy
Is a follow shot more accurate than a center-ball hit or draw shot?
This is definitely true for shots like the straight-up-and-down-the-table drill. Here are some possible reasons:

• It is easy for some people to hit the CB's center line when the cue tip is closer to the top of the ball where the top of the tip is more closely visually aligned with the top of the ball.
• The cue can be closer to level (not elevated) with a follow shot as compared to a draw shot with the same cue clearance above the rail. This will result in less swerve when the CB is hit slightly off center.
• When the CB is hit slightly off center, the effective squirt (the net effect of squirt and swerve) can be less with a follow shot vs. a draw shot (see "Squirt - Part III: follow/draw squirt and swerve" (Download) (BD, October, 2007). 
• The slowing drag effect of a draw shot increases the effect of the side spin off the rail. Both follow and draw shots will have the same amount of side spin (for the same amount of offset from the vertical center line); but with a draw shot, the CB will be moving slower at the rail causing the side spin to alter the rebound angle more.

FYI, some of this is described and illustrated in "Squirt - Part III: follow/draw squirt and swerve" (Download) (BD, October, 2007) and "Squirt - Part VIII: squerve effects" (Download) (BD, March, 2008).

Follow shots also provide the best speed and distance control (see optimal tip height for speed control in "speed control" section).

Also for cut shots, the "natural angle" of follow shots is very easy to judge and predict (see 30 degree rule in "30 and 90 degree rules" section for more info).

Ball hop
Why does the ball sometimes hop on a follow shot, and what can I do to reduce it?
Because the cue always has some elevation (because the butt must clear over the rails, and your grip hand requires some clearance if it is over the table), there is always a downward component of force on the CB that causes it to hop.

Also, an above center hits causes squirt into the table that adds to the downward component of force. Here's a good video describing and illustrating the effect:

To reduce the amount of hop, try keeping the cue as level as possible (i.e., less elevated) at impact with the CB.

With draw shots, the squirt effect cancels some of the cue elevation effect, because they act in opposite directions; however, the CB will hop with added cue elevation.  Here's an example: HSV B.24 - Draw shot with elevated cue and hop over an obstacle ball. (YouTube)

Friction force between the balls at impact can also cause the CB to hop, but this is small effect (see TP B.5 (Download)). Although, the effect can be exaggerated when the balls are clingy (e.g., old, dirty, and/or chalk-smudged). This effect is demonstrated in the following video: HSV B.46 - CB and OB hop and spin transfer during follow shots (YouTube)

If the CB is airborne when it hits the OB, the CB and OB can both hop after impact. There are other effects that can contribute to CB hop. If the CB is slightly larger than the OB (e.g., with an older "bar box"), the CB will hit slightly above the OB equator possibly causing both balls to hop (especially at higher speeds). For more info and demonstrations, see ball size and weight effects in "balls" section. A similar situation occurs if the OB is resting in a dimple or small tear in the cloth.

Another thing to be aware of whenever the CB is jumped or hopped is: If the CB hits the OB while airborne, the effective cut angle is changed slightly.  In this case, you need to aim for a slightly fuller hit on the OB, especially with fast-speed force-follow shots with the CB close to the OB. For an exaggerated example of the hop over cut effect, see: YouTube video here

For more info, see jump shot over cut effect in "jump shots" section.

Drag follow
What is drag follow, and how and when is it used?
A drag shot is where you hit the CB below center, and the bottom spin wears off and slows the CB down as it approaches the OB. With a drag-follow shot, all of the bottom spin wears off and the CB develops topspin roll before getting to the OB, resulting in CB follow. A drag shot can help reduce the effects of table roll-off (CB drift due to a non-level or dirty table), since the CB will be moving faster during the early part of the shot and be less susceptible to roll off. Drag can also be used to increase the effects of English. Here's a good example: YouTube video here

The drag action slows the CB, as the bottom spin converts to roll, and very little English is lost during the drag. This increases the effect of the English off the rail.

FYI, here's a related video for getting "quick" draw:
NV B.25 - Using draw and English to beat a scratch in a side pocket, with Tom Ross

Effects of tip offset, speed, distance, cut angle
On a follow shot, does it matter how high I hit the cue ball, if roll develops naturally?
Yes, depending on the shot speed and distance to the OB. At low speeds and large distances from the OB, it doesn't matter how high or how low you hit the CB, it will be rolling when it hits the OB (due to drag action). However, for fast shots close to the OB, the tip contact height makes a big difference in how much the CB curves after OB impact. As I pointed out before, the other important thing with follow shots is how much spin vs. speed the CB has after OB contact. A fast follow shot will create more follow action when the OB is hit more fully. Most of the speed is lost, but most of the topspin is retained, and there is more topspin with more initial speed and tip offset.

Force follow
What is force follow, and how and when is it used?
A force follow shot is a follow shot hit with maximum topspin and fast speed. This term is used mostly when referring to a nearly straight-in (small cut angle) follow shot. For more information and examples, see:

• natural roll, maximum offset, and over spin in this section
• HSV B.21 - Follow-the-rail trick shot (YouTube)
• HSV B.29 - Small-gap force follow shot (YouTube)

Natural roll, maximum offset, and over spin
What tip height is required for a rolling cue ball, and is it possible to get more spin than natural roll?
Good explanations and illustrations of this can be found in the following instructional article:
“How High or Low Should You Hit the Cue Ball?” (Download) (BD, September, 2011)

Here's an illustration from the article showing some key tip reference heights:

Concerning the amount of center ball offset required for immediate natural roll, the answer (and analysis) are in TP 4.2. (Download) The technical term for the contact point for natural roll is "the center of percussion." The required contact point offset from center ball is:
2/5 R = 0.4 R = 2/5 (2.125 in / 2) = .45 in

The maximum recommended offset, beyond which miscues are very likely, is usually cited in the range:
1/2 in to 9/16 in = .50 in to .56 in

Therefore, follow (topspin) in excess of natural roll is possible (i.e., .45 is less than .5), but not by much. This is called overs pin. With over spin, the CB will accelerate (i.e., speed up) as the spin wears off until the amount of topspin degrades to the "natural roll" amount. For more information, see "Coriolis was brilliant ... but he didn't have a high-speed camera - Part IV: maximum cue tip offset" (Download) (BD, October, 2005). HSV B.26 (YouTube) also provides visual proof of off-the-tip over spin, and provides more explanation. NV B.27 (YouTube) shows a simple experiment to show how difficult it is to achieve over spin without miscuing.

Now, after a CB hits an OB, it can most certainly have over spin. Before it hits the OB, the amount of topspin is the natural rolling amount (i.e., there is no "over spin"). After the CB hits the OB, the CB has more topspin than the natural rolling amount (i.e., there is "over spin"). This is what causes the CB to "follow" the OB to the rail. After rebound off the rail, some of the spin is retained (which looks like bottom spin now) causing the CB to draw back to the rail.

The reason for extreme follow effects is all about speed. For a fast natural roll follow shot, the topspin angular speed goes up as the ball linear speed goes up. And for small cut angle shots, the cue ball loses most of its linear speed and retains most of the spin, causing significant follow effects. HSV 4.1-4.3 (external web-link) illustrate the principles fairly well.

For more info and illustrations dealing with ball sliding and rolling, with and without side spin, see:
spin, slide, and roll in "English" section
cloth drag effects in "draw" section

Rail dribble
Why is it that with some follow shots, the cue ball stays close to the rail?
HSV B.21 - follow-the-rail trick shot (YouTube) illustrates and explains the effects fairly well.

With almost all follow shots (regardless of speed), the CB is "rolling" at object ball impact. This is certainly the case in the "rail dribble" video. With more speed, there is correspondingly more topspin, but the CB is still rolling (provided you are hitting the CB high enough).

The amount of follow action depends on how little CB speed remains in relation to the amount of topspin retained. With a fast follow shot, the CB has lots of topspin (as the ball rolls at a higher speed). With a smaller cut angle, most of the CB's speed is lost, but almost all of the topspin is retained after OB impact. That's what produces the follow "action" ... lot's of spin, not much speed. That's why both speed and cut angle are important in this type of shot.

If the cue ball has lots of topspin and very little speed when it hits a rail, "rail dribble" occurs.

For more info, visit billiards.colostate.edu

Fouls

Fouls in Pool and Billiards
... how to detect and avoid various types of fouls in pool.

(external web-link) for more information:
see Disc V of the Video Encyclopedia of Pool Shots

Double hits
How can you tell if a shot is a double hit or not?
The following video explains and illustrates how to detect and avoid a double hit in various situations:

For more information, see NV B.2 - Mike Page's double hits, push shots, and frozen balls (YouTube) and "Rules - Part II: double hits" (Download) (BD, September, 2009). The HSV DVD (external web-link) also has a nice feature on this. Also, many example shots, with explanations for the appropriate rulings, are available here: YouTube video

Clips HSV A.110-A.115 (external web-link) also show the effects of speed, cue stick elevation, and follow-through on double-hit avoidance for a chalk-width gap between the CB and OB. Unfortunately, clips A.110-A.112 and A.113-A.115 are from different viewpoints and were shot by different shooters with different amounts of follow-through, but the results are interesting nonetheless. Notice that the cue stick nudges the CB in mid air (i.e., the shot is a foul) in the 3rd (fast) stroke of A.112. This one is tough to call even with the high-speed camera.

The following videos show some interesting methods that can be used to avoid a double hit when there is only a small gap between the CB and OB: (YouTube Videos)

• NV B.49 - Using your knuckles to prevent a double hit and stop the cue ball, with Bob Jewett
• NV B.50 - Using your knuckles to prevent a double hit and get follow, with Bob Jewett
• NV B.51 - Using your natural forward stroke limit to prevent a double hit and get draw, with Bob Jewett
• NV B.52 - Using a fouette shot to prevent a double hit, with Bob Jewett

Here's some slow-motion footage of various fouette shots on YouTube

First contact legal hit
How can you tell if one ball is hit before another for a close-call legal hit?
See "Rules - Part IV: Which ball did you hit first?" (Download) (BD, November, 2009) and: (YouTube Videos)

• NV B.53 - How to determine which ball was hit first by watching the cue ball, with Bob Jewett
• NV B.54 - How to determine which ball was hit first by watching the object balls, with Bob Jewett

Also, for many example calls along with explanations, see: YouTube video here

from Scott Lee AZB post: (external forum-link)
A great test of "split hits" is something Jerry Briesath showed me 30+ years ago...freeze three balls together, with the odd ball towards the middle of the side pocket. Place the CB directly opposite the three frozen balls. Try to pocket the single OB frozen to the frozen pair, trying to get a split hit. You MIGHT make it once in a 100 tries. Move the CB right or left of the balls a few inches and you can pocket the OB every time. This is a proposition shot from decades ago.

Miscue
Is a miscue a foul if it results in multiple hits?
In the current rules, a miscue is a foul only if it is intentional.

HSV A.13-A.20 and A.98-A.109 (external web-link) show many more examples under different conditions. With most miscues, the tip slides along the cue ball, and the tip, ferrule, and/or shaft make secondary contact with the cue ball. The secondary contacts might partially explain the slapping sound you hear with a miscue. Normally, multiple hits on the cue ball results in a foul; but in case of a miscue, the multiple hits are not considered a foul under the current rules (unless the miscue is judged as "intentional"). For more information, see "Rules - Part V: miscellaneous fouls" (Download) (BD, December, 2009) and this video(YouTube)

One case where a miscue should be called a foul is when secondary contact clearly affects the shot. Here's a good example where the miscue might not be "intentional," but it should be ruled as a foul, because secondary contact is obvious: See YouTube video here

Another example where a miscue is a foul is with an intentional "scoop" jump shot.

Actually, an argument can be made that all miscues should be called as fouls. For one reason, miscues can create scuff marks and other surface damage on the CB (for an example, see: Is a Pool Ball Smoother Than the Earth?, (Download) (BD, June, 2013). Also, miscues with draw shots can easily damage the cloth. The following video of an elevated draw shot clearly illustrates why in this video(YouTube)

Also, the current rules require a single, non-prolonged, forward-stroke hit of the tip on the cue ball. All miscues involve the tip sliding along the cue ball (which can be considered "prolonged contact" and a non "single hit"), and most miscues involve secondary contact with the tip, ferrule, and/or shaft. Maybe all miscues should be called as fouls, because they are a result of either player error or intentional, unsportsmanlike play. However, the current "intention" of the rules is that only intentional and blatantly obvious "secondary contact" should be considered a foul. The shot in HSV B.28 (YouTube) is an example. Another example is where you miscue on a follow shot, and you trap the CB under the cue ... this embarrassing and unintentional miscue should also be called a foul, because there is obvious "secondary contact."

Push shot
What is a push shot foul and what are some examples?
A push shot is where a shot in which the cue tip remains in contact with the cue ball longer than is appropriate for a normal stroke and legal shot. A push shot is a foul (i.e., it is not allowed). Examples can be found in the following videos: (YouTube Videos)

NV B.2 - Mike Page's double hits, push shots, and frozen balls 
HSV B.28 - frozen-ball kiss, miscue, and push shots and fouls
Mike Massey trick shot collection

"Scoop" jump shot
Is a "scoop" jump shot a foul, even if there is no miscue or multiple hit?
Yes.
A scoop shot, in which the cue tip contacts the playing surface and the cue ball at the same time and this causes the cue ball to rise off the cloth, is treated like a miscue.
and a miscue is a foul if it is intentional (e.g., if use to purposely jump the CB over an obstacle).
The following video shows and explains what happens with various types of illegal "scoop" jump shots: YouTube video

Here's an example scoop shot resulting from an elevated draw shot miscue: YouTube video

For many example rule calls along with explanations, see "Rules - Part I: introduction" (Download) (BD, August, 2009) and this video(YouTube)

For more info, visit billiards.colostate.edu

Frozen Balls

Frozen Balls in Pool and Billiards
... how to aim, detect fouls, and prevent fouls with pool shots involving balls frozen together.

(external web-link) for more information:
see Disc IV of the Video Encyclopedia of Pool Shots

Aiming systems
How do you aim frozen-ball billiard and carom shots?
See:

• TP A.15 - Controlling the cue ball direction in a frozen cue ball shot (Download)
• NV B.55 - Bob Jewett's two-times-fuller frozen-cue-ball aiming system (YouTube)
• NV B.56 - Bob Jewett's ten-times-fuller frozen-object-ball aiming system (YouTube)
• HSV B.7 - one-pocket frozen-ball spot shot (YouTube)

Fouls
When it is a foul to hit into the CB when it is frozen to an OB?
When the cue ball is frozen to the object ball, you are allowed to hit into the cue ball toward the frozen ball with a normal stroke. A "push" stroke is not allowed.

Now, if there is a miscue during such a shot, it could be ruled a foul if there are obviously multiple hits or if the miscue is intentional. For many example calls along with explanations, see:

• NV B.63 - Instruction for pool rules quiz (part 1: CB frozen to OB) (YouTube)
• HSV B.28 - frozen-ball kiss, miscue, and push shots and fouls (YouTube)

Position control
How can you control the position of the CB when it is frozen to an OB?
See:

• NV B.48 - Frozen cue ball position control options (YouTube)​

For more info, visit billiards.colostate.edu

Fundamentals

Pool and Billiards Fundamentals
... how to play pool, and understanding and perfecting basic mechanics

see also: Online Pool Tutorial (external web-link) and
Top 100 Pool Tips, "Secrets," and "Gems" from menu page on GoPlayPool 101

Aiming
What are "best practices" and recommendations for aiming pool shots?
See:

• Dave's Aiming Method (DAM) aiming system in "aiming" section
• ghost-ball aiming in "aiming" section

Bridge
What are "best practices" and recommendations for proper bridge technique?
See:

• bridge technique advice in "bridge" section

Grip
What are "best practices" and recommendations for proper grip technique?
See:

• grip technique advice in "grip" section

Pre-shot routine
What are "best practices" and recommendations for the pre-shot routine?
See:

• pre-shot routine advice and "best practices" in "pre-shot routine" section

Stance
What are "best practices" and recommendations for proper stance technique?
See:

• stance advice and "best practices" in "stance" section

Stroke
What are "best practices" and recommendations for proper stroke technique?
See:

• stroke advice and "best practices" in "stroke" section

Vision
What are "best practices" and recommendations for proper visual alignment?
See:

• pool shot sighting in "eyes and vision" section
• "vision center" visual alignment in "eyes and vision" section

For more info, visit billiards.colostate.edu

Games

See "drills and games" section

For more info, visit billiards.colostate.edu

Grip

Billiards and Pool Grip
... how to hold or grip a pool cue properly.

external web-link) for more information:
see Section 2.02 in The Illustrated Principles of Pool and Billiards

Effects of light vs. tight grip
Can grip pressure affect the cue ball during tip contact?
The short answer is: No. The video below shows the hand grip during a firm stroke, striking the cue ball at the bottom of the pendulum swing. It is not totally clear from the video, but the hand flexes well after the cue ball is gone, as the hand accelerates the cue after it is slowed by the ball. The cue tip is in contact with the cue ball for such a short period of time (see tip contact time in "cue tip" section) and the hand flesh is so flexible compared to the cue tip, the grip cannot have any significant influence during tip contact.

Even the bridge hand cannot have any significant effect. The bridge hand flesh doesn't yield until a transverse elastic wave travels from the tip to the bridge after cue tip impact ... or during, if the bridge is within about 6 inches of the tip (for more info, see shaft end mass and stiffness effects in "squirt" section). But even if the bridge is close to the tip (which usually isn't the case), it takes time for the fingers to flex and generate force, and it takes time for that force to be "felt" by the tip. The CB will be long gone by the time this happens.

The grip hand does not generate much force until the cue slows and the hand moves forward enough (due to its momentum) to create enough skin flex. Again, the CB is long gone by the time this happens.

Bottom line: The CB is long gone before any "flesh effects" can be "felt" by the tip.

For related information, see: stroke acceleration in "stroke" section.

from Patrick Johnson:
Stroke and grip can't increase tip/ball contact time; the tip "bounces off" the CB on impact and your fleshy hand can't stop it no matter how tight your grip or how much your stroke is accelerating.

Even if you could increase tip/ball contact time this way, the effect on CB spin would be tiny - essentially the same as if you hit the CB a tiny bit farther from center (because the tip would be in contact while the CB rotates a tiny bit farther).

Can you get more cue ball speed with a tighter grip?
A tighter grip effectively adds more mass to the cue. So if you can deliver the cue to the ball accurately and with power, a tight grip would result in faster cue ball speed. However, a tighter grip usually results in less cue speed (and less accuracy) for most people.

from Spiderman (concerning whether grip tension has any effect):
Not on the cue, it doesn't. But it has a big difference on how you play.

I think it's been both theorized and verified that the impulse force during the brief contact far overshadows anything you can do by accelerating/influencing the cue during contact. There was a long thread on this last week.

On the other hand, from a shooter's perspective, a loose grip encourages you to let the cue travel naturally in line without swoop or wobble, and keeps you from shoving it off-line with a poor stroke. Almost everything will work better with the loose grip, but it isn't because of anything that happens during contact. It's because it makes everything before contact work in better harmony. It helps your "real" stroke follow the exact path of your warm-up strokes rather than being a somewhat-independent event.

If you could keep the cue flowing perfectly in line with a tight grip, it would work just fine, but most people can't do that - they will unintentionally pull it off-line. A tight grip also seems to sometimes manifest itself in a really bad habit where you try to "take something off" your stroke just before contact, and the decelerating cue condition is very prone to missing your intended tip-contact point. People who "take something off" are much more likely to miscue when trying to play the edges of the cue ball. Next time you miscue during a low soft draw, ask yourself whether you tried to pull your stroke just before contact. That is far less likely with a loose grip.

There are times when a tight grip is appropriate - for example, a nip draw to avoid a foul - but loose seems best for normal strokes.

For years I've had problems with tight grip and eye control (where I look during warm-up and delivery). I'm still working on both, and the more I work on it the better I shoot.

Technique advice
What are the recommended "best practices" for the grip?
This video covers all of the important technique elements:

Here's a good article (also Snooker oriented) that covers it fairly well: 
here (external web-link)

from Patrick Johnson (in relation to the "V" grip):
[Here's] the starting place for the way I (and I'm sure many others) teach the grip. Gripping the cue between the thumb and index finger this way, with the other three fingers held off the cue, does a couple of things:

1. It grips the cue at only two points on opposite sides of the handle (like having a horizontal hinge pin through the handle to form a "pivot point") so the cue can pivot freely during the pendulum stroke without interference from the rest of the fingers on the grip hand.

2. It puts the hand in the proper "hanging straight and loose" position so the wrist joint pivots easily along the same line as the cue and shot line without "steering" the stroke offline.

But pointing the thumb and index finger down is only the starting position - the grip is used this way at first to illustrate the hand position and how the cue should pivot between the thumb and index finger, but it's not the finished grip.

The next step is to allow the index finger to wrap lightly around to cradle the bottom of the cue so that less "pinching" pressure is used (unless needed for harder shots) - the thumb remains more or less straight down on its side of the cue, curling inward only enough to complete the loop with the index finger. The remaining three fingers are kept off the cue for some more time until the feeling of cradling the cue lightly with only the thumb and forefinger comes naturally.

Finally, the remaining three fingers are allowed to relax comfortably against the cue and even curl lightly around it, but without applying any grip pressure. All grip pressure comes only from the "pinching" of the thumb and forefinger against the sides of the cue. When done correctly, this grip develops calluses on the insides of the thumb and forefinger on opposite sides of the cue where it pivots against them.

The "v" in this method is simply the inverted "v" formed between the thumb and forefinger, made more visible by the gap left between it and the top of the cue because of the loose grip.

For more info, visit billiards.colostate.edu