How can physics analysis and understanding help my pool game?

The purpose of the physics analyses and discussions isn’t always just to help make your game better. Often, it is just to help develop a better understanding of what is going on with the physics. Now, sometimes that improved understanding can help lead to insight and technique advice that can help at the table. Two good examples are the 30° rule and squirt, swerve, and throw effects. In both of these cases, the insight gained from the physics can go a long way to helping people develop and improve faster. Also, for some people, understanding can help improve confidence. Anytime one can back up intuition with understanding, one will usually have more confidence. That way, when one gets down in the stance, one can better focus on confidently executing the shot, without having to subconsciously doubt one’s intuition.

Now, top players who have perfect intuition don’t need to “understand” the 30° rule peace-sign technique, or how to achieve maximum throw, or the effects of inside vs. outside english, or rail cut-shot physics, because they instinctively know all of this stuff based on intuition and confidence built from years and years of successful practice and play. They “just know” where the balls will go on every shot. However, for everybody else, a little knowledge, understanding, and insight can help one improve faster and have more confidence.

Regardless, nothing beats endless hours of purposeful practice and successful experience. And even with knowledge and understanding, lots of practice time is still required to create the intuition and feel necessary to apply the knowledge and understanding. However, this doesn’t mean that knowledge and understanding is a bad thing. For the many people who don’t have the desire or ability to dedicate a large percentage of their life to table time, the knowledge and understanding can help them progress faster and be more efficient with their limited practice time. For the few people who are able to dedicate enormous amounts of time at the table, the knowledge and understanding aren’t as important because they will develop an intuitive feel for everything as the Game teaches them, assuming they don’t have extreme technique flaws and/or gross misunderstandings that limit or dramatically slow their development.

Another important point is that knowledge and understanding should not cause you to over think a shot. More importantly, one should definitely not be thinking during a shot. However, it can sometimes help a lot to think before a shot. Intuition and feel created by countless hours of purposeful practice and successful experience also helps.

See also:

For useful resources for learning pool physics, see:

Is there anything wrong with not understanding pool physics?

No, but sometimes it can cause misconceptions and lead to many pool myths. Here are some classic examples where people sometimes have “physically incorrect” thinking but get the desired results anyway:

  1. “On a break shot, aim and hit the CB below center to squat the rock.” To park the CB in the center of the table on a power break shot, the tip must actually hit the CB slightly above center; although, with elbow drop common with a power break, one must aim below center so the tip will end up hitting slightly above center (see BU break advice video).
  2. “To get good draw action on a straight shot, you need to elevate the cue.” This is completely wrong, but it might help some people get more draw. One reason is that some people don’t aim low enough on the CB, or they drop their elbow during the stroke into the ball. By elevating, they might be getting a lower effective tip position due to the downward angle of the cue (see cue elevation tip offset illustration), and the elevated stroke might change the timing of their elbow drop. For more info, see the cue elevation effects resource page.
  3. “The type of stroke directly affects the action of a shot.” In reality, all the CB “cares” about is the hit (cue speed, tip contact point, and the direction of the cue at contact with the CB). For more info, see the stroke “type” and “quality” resource page.

Good shooters don’t think about physics when they play. Why should I try to learn or understand this stuff?

All good pool players have a very good understanding of many “pool physics effects” (not equations, but real effects at the table):

  • how stun makes the CB head perpendicular to OB motion in the tangent line direction.
  • how a rolling CB heads in the natural angle direction over a wide range of cut angles.
  • how backspin makes the CB come back and topspin makes it go forward.
  • how backspin wears off and converts to stun and then topspin, especially with more distance and less speed.
  • how sidespin changes the rebound angle off cushions.
  • how to adjust aim to compensate for CB deflection and throw.
  • how a drag shot intensifies sidespin.
  • how gearing outside english can eliminate throw.
  • how throw affects frozen or small-gap combination shots hit from different angles.
  • how cut-induced spin affects bank shots.
  • how to use cue elevation to make the CB curve.
  • how hitting down on the CB can make it jump.
  • how hitting rail cut shots ball-first vs. cushion-first with sidespin totally changes the action of the shot.


One might not consider “pool physics” consciously or think about the math behind it (which would be silly at the table), but one does make decisions based on an intuitive and experience-based understanding of all pool physics effects (whether one admits or is aware of it or not).

Now, one should not be doing any of this thinking or decision making while one is down on a shot, ready to shoot. If one does this, one probably won’t be an effective or consistent shooter:

Think before your shoot … not during.

For people who don’t yet have complete “pool physics effects” understanding from countless years of successful practice and experience, improved knowledge can help speed the learning process, limit frustration, and improve effectiveness at the table.

Many examples of how physics-based knowledge and/or understanding can be useful at the table can be found here:

Do you need to take a physics class or learn complicated math to use this stuff at a table? No! But a little “understanding” and/or “intuition” can go a long way.

You can learn this stuff through countless years of trial and error, but some people can learn it faster by getting instruction and by reading and watching high-quality instructional materials. But to execute shots accurately and consistently, one must practice, and some people practice smarter and improve faster than others. Having good and consistent fundamentals and mechanics can also help speed this process. This foundation can also be developed through countless years of trial and error, but learning and understanding can also help speed the process.

Again, all good pool players are masters of “pool physics effects.” They have also put in enough table time to be able to apply their understanding and execute shots with confidence and consistency (see knowledge can be useful, but you still need skill).

from Poolplaya9 (in AZB PM):

Your arguments for the benefit of the correct physics knowledge seems to essentially be that it can shorten the learning curve and improve confidence. As food for thought, I think there are a couple of other benefits which I can’t recall having seen addressed anywhere.

We know that our subconscious figures most of the physics out (given enough experience) even if our conscious mind doesn’t know the physics, otherwise we would miss a lot more. But I strongly suspect/believe that whenever the knowledge that your subconscious has is in conflict with the beliefs of your conscious, it will lead to more errors. The subconscious is certainly “dominant” and overrules the conscious belief the vast majority of the time, but the conscious creates enough “static” or “interference” or has enough influence to overrule or hinder or disrupt the ability of your subconscious to do its job enough to cause it to fail more often than it otherwise would have if you had the correct conscious beliefs it wasn’t having to deal with this conflict in knowledge. I’m writing this quickly so hopefully that made enough sense.

In others words, using made up but illustrative figures, your subconscious is going to do the correct physics calculations for a shot 98.5% of the time even when you have incorrect beliefs about the physics involved in the shot, but when your beliefs about the physics involved are correct your subconscious will make the correct calculations 99.8% of the time because there is no conflict that can interfere with or muddy the waters of your subconscious. I believe this premise likely holds true at all levels, including pro, and think this may be one of most important advantages of knowing the correct physics.

While not nearly as certain, I also think it may be the case that certain physics involved in the game may never be fully and adequately learned by your subconscious, with one of the reasons being that the specific physics involved were never isolated enough for the brain to fully recognize and comprehend their impact due to the complexity of all the other variables involved.

So I think it may be possible that your subconscious will never learn certain things quite as well as it would if you had the correct conscious knowledge of the physics involved, and am more certain that your subconscious (which is most responsible for how we execute shots) will be more prone to error when it has to deal with conscious beliefs which are in conflict with what it has determined. Again, hope that all made enough sense the way I quickly typed it out. It is mostly just food for thought in case you feel there could be anything to it and hadn’t considered it before (highly unlikely and it could be that one or both of these are part of what you are talking about when you refer to the potential benefit from increased confidence), but I also welcome comment if you feel any comments are in order.

from lfigueroa (in AZB post):

The equations don’t mean squat.

When you are leaning over that critical shot, it is all about those hours you’ve spent hitting countless balls into the pockets, how much attention you’ve paid during that time, and what you have taught yourself during those hours.

Don’t get me wrong.

The equations are interesting. To some they are fun and I believe there is no such thing as “too much knowledge.” Certainly there can be no harm in learning and understanding them. But a great pool player they do not make. But I think we sometimes make the mistake in this group of placing way too much emphasis on the x and y of it, instead of practical ways to learn the physical act of shooting pool balls. Stance, head position, bridge, grip, levelness of cue, and delivery are what it’s about. Now before the science guys (and wannabe science guys) go ballistic, I want to say that I like the diversity of the group and the fact that you can go from the discussions about gyroscopes to the first person accounts of road trips taken.

But my point is that it’s become impossible not to notice the almost elitist disdain meted out by those wielding slide rules against those that advocate “just hit the damn ball.” Whether the science guys like it or not, these folks are closer to the truth and pass the test of Occam’s Razor better than any equation. What makes a great, or at least a better pool player, is hours on the table, not hours on the calculator.

Though I have been called “a natural” when it comes to pool, nothing could be further from the truth. I work hard to achieve the modest success I occasionally enjoy. I do believe that as in other walks of life there are some people who are complete and total naturals when it comes to a particular skill. It is, in many respects, like setting out on an attempt to conquer Everest. Some people stumble upon the mountain pass shortcuts that lead them, almost effortlessly, to the top, clear weather all the way. They pick up a pool cue and their physique, natural setup, and God given hand-eye coordination, makes them play extraordinarily with virtually little cognitive effort. Others have Sherpas that guide them through via the shortest passes to the summit. But the majority of us read the maps and books and struggle up the mountain, sometimes weathering blizzard conditions that necessitate camping out on the whatever outcrop we can find. Despite all our study, work, and preparation, the journey is sometimes hardest and longest for those of us in this camp.

So to wrap this up, I’ll just say that IMO the simple, ultimate secret about pool can be found on page 46 of Capelle’s “A Mind for Pool.” It sits there waiting in black and white for anyone who stumbles upon it:

“The big secret is that there is no single big secret.” 

No aiming system, no aim and pivot, no backhand english, no equations.

Just hit the damn ball…. over, and over, and over again.

[Also,] if the myth makes you run more balls and makes the cue ball go where you want, go with the myth and forget the science.

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