accelleration

[dr_dave]

As others have said, DEcelerating just prior to impact is bad. But ACcelerating is bad too. You want the stick going at a constant speed.

You Won't get different action if you are accelerating. That is, and I know this is counter intuitive, the fact you're actively pushing the stick just prior to impact makes no difference on the outcome.

Most of the time that folks FEEL like they're accelerating at impact, they're actually going at a constant speed.

Regardless of whether you're accelerating or not, the stick right after impact will show down to about half it's speed. A heavier stick will slow down less, but still almost by half.

Actually it is much closer to 1/3 that the cue speed decreases.

The exact amount of slowing depends on cue weight; but for typical equipment, the slow down is about 40%. So I guess you are right ... 40% is closer to 33.33% than 50%. Regardless, the exact number isn't so important, IMO. What's important is the speed and lack of deceleration (or acceleration) of the cue at ball impact. For more info, see:

http://billiards.colostate.edu/threads/stroke.html#acceleration​

Regards,
Dave

 

[Cdryden]

For what its worth Max Eberle explained this really well in his "Powerful Pool" instructional video. It's worth a look and comes with allot of good fundamental info. Not trying to push his stuff on you but I have been using his video recently and he covers this topic pretty well.

Edit; others on here also have some good instructional material that covers this, it's just that Max's video is the one I am most familiar with.

 

[dr_dave]

The exact amount of slowing depends on cue weight; but for typical equipment, the slow down is about 40%. So I guess you are right ... 40% is closer to 33.33% than 50%. Regardless, the exact number isn't so important, IMO. What's important is the speed and lack of deceleration (or acceleration) of the cue at ball impact. For more info, see:

http://billiards.colostate.edu/threads/stroke.html#acceleration​

Curious--40%, calculated or observed?

Observed, per HSV B.40 - Stroke speed and acceleration analysis, with Bob Jewett. However, the value agrees with theoretical results (see Equation 21 in TP A.30, using typical values for physical parameters).

Looks like an accelerometer was used.

Nope. See the video.

Using a quick conservation of momentum and assuming elastic collision, 20oz cue, 4oz ball, U1/V1=(20+4)/(20-4)=10/15=.667

The tip-ball collision is not very elastic (i.e., significant energy is lost). Also, we were using a 19oz cue. Also, pool balls are 6 oz, not 4 oz.

Agreed that it doesn't really matter.

Agreed.

Regards,
Dave

 

[ShootingArts]

might as well poke things with a stick

The exact amount of slowing depends on cue weight; but for typical equipment, the slow down is about 40%. So I guess you are right ... 40% is closer to 33.33% than 50%. Regardless, the exact number isn't so important, IMO. What's important is the speed and lack of deceleration (or acceleration) of the cue at ball impact. For more info, see:

http://billiards.colostate.edu/threads/stroke.html#acceleration​

Regards,
Dave

Dave,

It doesn't really matter what the stick is doing, accelerating, slowing, or constant speed at impact. The same amount of force imparted to the cue ball in the same place at the same angle will get the same result. This thread has turned into a discussion of the effect when the cause is what is important, what the muscles and connective tissues in the torso, shoulder, arm, and hand are doing, the state they are in, at impact. Even then it can be demonstrated that multiple approaches work. I prefer the muscles in mid contraction. Others prefer for gravity and cue weight to do most or all of the work. I prefer a more natural motion while most current instructors favor a combination of motions and attempts to hold some areas rigid that only occurs in pool.(cue sports)

Many techniques can work and "best" really depends on the individual. I think when it comes to applying sound body mechanics that the pool world is fifty years or more behind other sports though.

Hu

 

[dr_dave]

It doesn't really matter what the stick is doing, accelerating, slowing, or constant speed at impact. The same amount of force imparted to the cue ball in the same place at the same angle will get the same result...

Agreed, but speed-control consistency might be different for different people with different techniques. For more info, see the explanations here:

http://billiards.colostate.edu/threads/stroke.html#acceleration​

Regards,
Dave

 

[Slh]

if you want an advice, try to use a back pause just like all the snooker players do. Pause- bring the cue back- pause and than shoot. Also alex pagulayan use this tecnique.
This video can help:
http://www.youtube.com/watch?v=uRVxIhAIFdk
I don't say to have that long pause, but I use a faster "version".

A lot of players bring the cue back fast and decelerate, with the back pause you are 100% sure you are accelerating trough the cueball

 

[justnum]

so kinda what your saying is my cue should hit the cb when my stroke is on the upswing?

If a pure physicists debate that the forces are balanced at the low point of a pendulum and that the bottom point of the swing is the best moment to strike the cue ball with the cue tip, then they are right all the energy in a pendulum is transferred when at its lowest point.

However the arm is not a pendulum, the muscles in your arm create forces. During the upward motion, your bicep contracts (in physics it is called compression) and produces additional force. If you don't have biceps, then you should use the pendulum stroke.