English and how it affects the CB and OB

[TheProfessor]

I am working on improving my positional play, so in addition to drawing the cue ball and applying top spin, I am working on my left and right english shots. I have noticed that this really throws off my aiming, and I am wondering if I am doing something wrong, or if I should be able to correct for the english by changing my aiming.

Let's say I hit a draw shot with right hand english. Immediately after I strike the cue ball, it seems to veer to the left just a bit...then as it rolls further down the table it veers back to the right. Also, when it contacts the object ball, the english is transferred and "throws" the object ball some. Of course, as the distance changes between the cue ball and object ball, the amount of english and throw changes. Does this make sense to you all? Am I doing something wrong, or is this perfectly normal and I have to change my aiming to account for all of these forces? Is there a resource online somewhere that better explains all of the spin involved? I have numerous pool books but none of them delve into the complexity of english and how it affects your aiming.

thanks so much!

 

[Jal]

...Let's say I hit a draw shot with right hand english. Immediately after I strike the cue ball, it seems to veer to the left just a bit...then as it rolls further down the table it veers back to the right. Also, when it contacts the object ball, the english is transferred and "throws" the object ball some. Of course, as the distance changes between the cue ball and object ball, the amount of english and throw changes. Does this make sense to you all? Am I doing something wrong, or is this perfectly normal and I have to change my aiming to account for all of these forces?

Yes it does make sense and you're not doing anything wrong. In fact, you're very observant.

The initial veering to the left is called squirt (or deflection) and its amount is a property of the cuestick and how far off to the side you strike the cueball. Some sticks produce a large amount of squirt and some are designed to produce very little.

The subsequent veering back to the right is called swerve. It's caused by the sideways spin placed on the cueball and the fact the axis of spin is slightly tilted away from a perfectly vertical direction. If you could shoot with the cue perfectly level, that is, parallel to the table's surface, the spin axis would be perpendicular to the table's surface and there would be no swerve. On virtually every shot the cue is inclined with the rear raised up a bit, so you do get swerve whenever you apply english (sidespin). The more the cue is inclined (usually called "jacking up" when the butt end is raised higher than normal), the more swerve you get.

The final direction of the cueball is, curiously, completely independent of the amount of friction between the ball and cloth, even though the swerving is caused by it. How long it takes for the ball to achieve its final direction though, does depend on it.

... Is there a resource online somewhere that better explains all of the spin involved? I have numerous pool books but none of them delve into the complexity of english and how it affects your aiming.

You can find out a lot about by searching the various pool forums. While the effects can be calculated and thus predicted quite accurately, I don't think you'll come across any easy formula or method for adjusting for squirt, swerve and object ball throw. The best thing is to develop a feel for it at the table. However, understanding the basic principles should help the learning process somewhat, but don't get bogged down in the study. You can't compute these things while lining up a shot.

Here are two good resources for discussions of the various physical phenomena as applied to pool:

http://www.sfbilliards.com/articles/BD_articles.html

http://www.engr.colostate.edu/~dga/pool/

Jim

 

[Nico]

When you use right hand english on the cueball, it initially travels to the left because of what is referred to as "Squirt". You are knocking the cueball off it's straight trajectory by the off center hit and the force of contact. The reason it curves back to the right is becuase you are using right english, and once the english takes, the cueball will head in that direction.

Also, english between two balls are like sprockets. Whatever you put on the cueball gets reversed onto the object ball. If you use right hand english on the cueball, it will cause the cueball to curve right, and when it contacts the object ball, it will impart left hand spin causing the object ball to throw left. This is called spin-induced throw.

The throw, squirt and curve often cancel each other out and the shot goes in as intended. Often we under or over-cut a shot and the throw, curve and squirt become a greater factor causing you to miss a shot. Then there's collision-induced throw to worry about. If you are cutting a shot at a small angle and hitting it very heavy, you will throw the object ball ahead of the intended line of aim. When cutting a ball by hitting it very thin, collision induced throw is hardly a factor.

The way to solve this is learn how to play angles better so you can get away with using less english. As a general rule I never use more than 1 tip of english, but then I give myself strong angles and keep the cueball off the rails. When you can move the cueball with a strong angle using a centerball hit and get good position, you will have less difficulty in running out. Some teachers say you shouldn't be using english until you can run a rack using only vertical-axis spin. Something to think about.

 

[TheProfessor]

thank you Jim, that makes a lot of sense and I am glad to see that I am not doing anything wrong. I was starting to think that the better players don't have to deal with these forces because of their stroke or bridge, but I see that they have just mastered the aiming and are very accurate whether they are shooting the CB right in the middle or with extreme left english.

 

[TheProfessor]

Nico, thanks for your advice as well. One more thing that I have noticed...it seems that if I hit a cut shot with extreme backspin, it sharpens the cut and I end up overcutting the OB. I have started aiming slightly differently on these cut shots, depending on how much draw or topspin I am applying to the CB. Is this normal as well?

 

[Nico]

Nico, thanks for your advice as well. One more thing that I have noticed...it seems that if I hit a cut shot with extreme backspin, it sharpens the cut and I end up overcutting the OB. I have started aiming slightly differently on these cut shots, depending on how much draw or topspin I am applying to the CB. Is this normal as well?

When you use bottom spin, it imparts top spin on the object ball. This shouldn't necessarily cause you to miss a shot though. It's possible when you go very low on the cueball that you are unintentionally applying side spin as well.

When you are playing a cut shot, try just focusing on the pot and soft roll it in using minimal english, (whenver possible of course). These shot are tough enough on their own and don't need to be complicated by extreme spin. Also, you may be throwing your stroke off using extreme draw. If you are needing to use extreme english regularly, consider working on your leaves, by this I mean the positional angles you leave yourself. You shouldn't need to use serious english very often, you may be moving the cueball too much or not enough.

Don't overthink this crap, once you understand it, put it away in your memory banks and hit the poolhall. Practice your shots with english, but practice getting the shape that allows you to stay closer to the center of the cueball. Watch players like Corey Dueul and Marcus Chamat, these guys play pocket speed to a "T" and understand angles.

 

[Colin Colenso]

I am working on improving my positional play, so in addition to drawing the cue ball and applying top spin, I am working on my left and right english shots. I have noticed that this really throws off my aiming, and I am wondering if I am doing something wrong, or if I should be able to correct for the english by changing my aiming.

Let's say I hit a draw shot with right hand english. Immediately after I strike the cue ball, it seems to veer to the left just a bit...then as it rolls further down the table it veers back to the right. Also, when it contacts the object ball, the english is transferred and "throws" the object ball some. Of course, as the distance changes between the cue ball and object ball, the amount of english and throw changes. Does this make sense to you all? Am I doing something wrong, or is this perfectly normal and I have to change my aiming to account for all of these forces? Is there a resource online somewhere that better explains all of the spin involved? I have numerous pool books but none of them delve into the complexity of english and how it affects your aiming.

thanks so much!

I think what you are observing is more about throw, than squirt or swerve, which are negligable over small distances. Though all 3 are very important and need to be compensated for depending on the type of shot.

Here is a thread that talks about a system to deal with this:
http://forums.azbilliards.com/showthread.php?t=23348&highlight=System

 

[Jal]

...it seems that if I hit a cut shot with extreme backspin, it sharpens the cut and I end up overcutting the OB. I have started aiming slightly differently on these cut shots, depending on how much draw or topspin I am applying to the CB. Is this normal as well?

Yes it is. Whether players realize it or not, as they learn to make shots they learn to compensate for throw. Throw is caused by friction between the balls' surfaces and has both a magnitude and direction. Its direction changes depending on the spin on the cueball. When you have a lot of draw or topspin on the cueball, the direction of the friction, and thus the throw, is much more oriented toward the straight up or down direction, respectively. The sideways component of the throw is consequently reduced to a relatively small value.

The magnitude of the friction force is also reduced considerably as the surface speed between the balls increases, and increased as the surface speed decreases.

Both effects have to be adjusted for. It's quite natural to overcut hard shots or those with a lot of draw or follow because of them. A little thicker hit is called for.

Jim

 

[HitHrdNDraw]

Practice makes perfect

Its impressive that you noticed how the ball "throws" with english applied however, in my opinion, dissecting the physics of aiming with english is great for books and journal articles but you can't tell someone how to adjust for the deflection and throw of a ball. you just gotta practice. same shot... over and over again... once you semi-master it, you will automatically compensate for the applied english, even if it is a table you aren't used to it only takes a few shots and you are right in stroke... its good to know how balls will react so you know kind of what to expect, but there is no substitute for practice... just my two cents...

 

[Slasher]

My best advice is to put the spin on even before you bend over, in other words align your body with the spin in mind, this way you are stroking along the line of the shot rather than accross the line, which is what will occur if you get down and then adjust for spin.
Hope this makes sense and helps some.

 

[mikepage]

[ Am I doing something wrong, or is this perfectly normal and I have to change my aiming to account for all of these forces? [...]

Perfectly normal and yes.

While others have offered good responses, here's a post I make quite some time ago when somebody on RSB asked nearly the same question.

Aiming with english:

A shot hit with sidespin is a fair amount tougher than the same shot hit without sidespin, so consider adding
english only when the object ball is fairly close to the pocket and the
cueball is not too far from the object ball. *The primary objective of the
english is to alter the angle of the cueball rebounding off the cushion. *

There are three new things to consider when hitting with sidespin:
spin-induced throw, swerve, and squirt. *

spin-induced throw: *when a spinning cueball hits an object ball straight
on, the cueball rubs across the object ball and "throws" it off
course a little bit. *This is a small effect (due to the friction between
the balls), but it's not small enough to be ignored. You will see this
effect plain as can be if you set up a shot with the object ball six feet
from the pocket and the cueball just four or five inches from the object
ball. *

swerve: *IF a cueball is hit with sidespin using a level stick, it will
move in a straight line. *However, even though as-level-as-possible is the
goal, the stick is never really level. *You are always hitting down on the
ball at least a little. *Hitting down on the cueball when applying
sidespin generates "swerve." *The cueball actually curves to the side you
are hitting on. *If you hit easy, the cueball will curve a little bit
within the first few inches and then move in a straight line along the new
direction. *If you hit harder, it will go further before curving. *If you
hit harder still, or if the object ball is close, it may *get it's job
done before curving. *Adjusting for this is complicated and depends on the
cloth on the table. *This is the reason I advised against using english
when the cueball has far to travel before hitting the object ball. * You
will see swerve plain as can be just by hitting the cueball not too hard
the length of the table with an elevated cue and sidespin.

squirt: *(also called cue-ball deflection) This is a tough one, in part
because it is different for different sticks. *Imagine you hit a cueball
at 9:00 with a completely level cue (so there's no swerve), and you got to
the aim by lining up for a centerball hit and moving the whole cue
parallel till the tip is pointing at the 9:00 spot. *IFF there was no squirt, the cueball would go in exactly the
same direction as the centerball shot would have (parallel to the line of
the stick). *However, because the front of the stick on sidespin shots is
driven even more off to the side during the stick-ball collision, the
cueball must go off to the other side a bit. (Every action has an equal
and opposite reaction, or conservation of sideways momentum, or whatever
you want to call it). *The result is the cueball goes off in a straight
line that is angled off a bit (as much as 3 or 4 degrees) from the line of
the stick. *The magnitude of this effect is different for different
sticks.

So how about aiming? *For the conditions I recommended as ripe for
english, squirt is the main problem. * The move-the-stick-parallel
approach(your second suggestion) is not right for any cue. *Your first
suggestion *(pivot about the butt of the cue) is close to correct for the
extreme lowest squirt sticks available. *The correct aim for most sticks
would be achieved by beginning with a stick lined up centerball, and then
pivoting the stick about some point between your bridge hand and the joint
of the cue. *The optimum point is different for different sticks. *If it
is, say, 15 inches back from the tip, then you would apply left english by
leaving that 15-inch point fixed and moving the butt of the cue to the
right until the tip is where you want it. * Many sticks "pivot points" are
not too far behind the bridge hand for a longish bridge. *So some people
actually aim centerball and then pivot about their bridge hand. *This is
called aim-and-pivot (or sometimes backhand english). *

Most strong players do not use any such system, in part because it's
awkward to pivot about the correct point, and in part because there are
swerve and throw to consider as well on many shots. *Many strong players
who have been using the same cue for a long time have probably hit 100,000
shots with english using that cue. *They develop a memory *(an intuition)
of how to adjust depending on the the shot and the speed, etc. *In fact
there are many strong players who would not be able to explain coherently
these effects and what they depend on, but they have a working knowledge
of what they need to do in actual situations. *Some people swear by the
intuition/working knowledge as the true path to salvation and are
downright antagonistic of efforts to break it down and understand the
different effects. *But the correct opinion [ ] is that enlightenment
is a harmonic convergence of the yin and yang of knowledge and intuition.
Your knowledge and understanding is a guide for developing that intuition
and is profitably kept close by.

mike page
fargo

 

[TheProfessor]

thank you all for all of the explanations. it all makes perfect sense now. several of you advised not hitting english shots unless it is absolutely necessary for position. however, i see the pros hitting draw shots with left or right english all of the time...is it because they are so good that they can make these shots without effort? should i not bother with these types of shots until my game is at a near-pro level? would love to hear your thoughts on this.

thanks for all of the knowledge!

 

[jsp]

...should i not bother with these types of shots until my game is at a near-pro level?

You will never come close to "near-pro level" if you DON'T incorporate various english shots to your game. Once you can consistently make farily long straight in shots, then you should attempt incorporating different types of english shots to your game (if the shot calls for it).

jsp <~~~ still working on my straight in shots

 

[pete lafond]

You will never come close to "near-pro level" if you DON'T incorporate various english shots to your game. Once you can consistently make farily long straight in shots, then you should attempt incorporating different types of english shots to your game (if the shot calls for it).

jsp <~~~ still working on my straight in shots

Yes, Yes, Yes...

English is so important in the game of pool and it is never to soon to begin using it and understanding it. It does not matter how great a player is able to play position and patterns, there are some shots and especially in 9 ball that you know in advance that English will be necessary.

A very beginner that has never run a rack maybe stay away, but the earlier the better and the more precise the intended tip to CB contact is learned as a result. NOT knowing English is why beginning players miss out on hitting and understanding center ball.

 

[pooltchr]

When you use bottom spin, it imparts top spin on the object ball. .

If this is true, should I be able to use top spin and impart back spin on the object ball???

 

[Colin Colenso]

If this is true, should I be able to use top spin and impart back spin on the object ball???

The effect is so small as to be almost negligable.

Though I believe it is worth considering if two OB's are planted such that the first needs as near to 90% deflection to be pocketed and the thin cut is inconvenient for CB positioning...or access.

In this situation, I will play onto the combination with follow, rather that stun or draw as it can help the first OB deflect at closer to 90 degrees.

Conversely, if you have two balls touching or near to touching in a straight line, and you want the first ball to follow through and be pocketed, then a firm draw shot can impart some topspin on the first OB and help it to move forward. Accuracy of shot becomes paramount.

 

[Nico]

If this is true, should I be able to use top spin and impart back spin on the object ball???

It's easy for the CB to transfer topspin on the OB as the OB will be rolling forward anyway. In order to reverse the spin of the OB, you need a lot of juice since you're asking that ball to spin against it's own momentum and weight. Usually, the OB slides and then starts to roll forward once the little bit of backspin is rubbed off.

The main circumstance when I use bottom on the CB in order to impart topspin upon an OB is; if I want to shoot one of my balls through another OB that's blocking a pocket (8-ball). This way after my ball knocks the blocking ball in, it still has topspin and follows it into the pocket.

I use this technique all the time to pot the eightball into a pocket that is otherwise completely blocked.

 

[pooltchr]

Usually, the OB slides and then starts to roll forward once the little bit of backspin is rubbed off.

.

So if I am shooting with draw, the ob doesn't slide at all, it just starts rolling forward immediately???

 

[Jal]

So if I am shooting with draw, the ob doesn't slide at all, it just starts rolling forward immediately???

Yes it slides before it starts rolling. In fact, if you put an optimal amount of draw on the cueball, the object ball will start off with only about 1/10th of the topspin it would have if it were rolling. In other words, if it collides with another object ball head on immediately, it will behave as if it were rolling, but moving as a whole at 1/10th of its actual speed. This is about the maximum spin you can put on it, although it varies a little with shot speed, a little more for soft shots and a little less for very hard ones.

To get this amount of topspin on the OB, contrary to what some may think, the optimal amount of draw on the cueball has to be about 1/3 of maximum, and it's the amount of spin the CB needs to retain upon impact (not rubbed off on the way to the OB). It also varies a little with shot speed, slightly more for a lag speed shot, and slightly less at twice lag speed.

By the way, the 1/3 of maximum CB spin to get maximum spin (and throw) on the OB applies to any straight or nearly straight shot. Using more than this is a waste of perfectly good spin. In fact, it diminishes it considerably.

Jim

 

[pooltchr]

Do you know if anyone has any video that would back up this theory? I was always of the belief that the ob always skids first after impact and that any kind of spin on the cue ball doesn't affect the roll of the ob.
Steve