Pivot Point Question

[Angle Detective]

Since we all stroke with the rear hand and keep a stable bridge hand, wouldn't it be counterproductive to have a pivot point, measured from the tip, longer than your bridge hand?

The bridge pivot seems not only to be good for back hand english purposes, but if that bridge pivot equals the pivot point of your cue it becomes a way to ensure that any wavers in your stroke will still pocket balls. I've seen measurements of pivot points of very low deflection cues around 20". This would require a very long bridge in order to make sure you have this pivot point insurance.

 

[Bob Jewett]

Since we all stroke with the rear hand and keep a stable bridge hand, wouldn't it be counterproductive to have a pivot point, measured from the tip, longer than your bridge hand?

The bridge pivot seems not only to be good for back hand english purposes, but if that bridge pivot equals the pivot point of your cue it becomes a way to ensure that any wavers in your stroke will still pocket balls. I've seen measurements of pivot points of very low deflection cues around 20". This would require a very long bridge in order to make sure you have this pivot point insurance.

I think pivot point swoop cancellation is the only good argument for relatively high-squirt sticks. There is the small problem that for each particular shot, taking into account speed, desired amount of side spin, distance to the object ball, elevation, ... there is a different effective pivot point, and therefor you want a different bridge length. You can probably still get some benefit on average shots with an average bridge.

Ron Shepard pointed out that for a break stick -- constant bridge length, constant speed, constant elevation, and constant distance to the ball -- a pivot-point bridge is probably the way to go.

 

[Angle Detective]

How far can the effective pivot points be from one another for different shots?
I was under the assumption that no matter how hard you stroked and no matter how much english you used the pivot point balances things out.
Thanks.

 

[Jaden]

IT mostly does.....

How far can the effective pivot points be from one another for different shots?
I was under the assumption that no matter how hard you stroked and no matter how much english you used the pivot point balances things out.
Thanks.

It doesn't vary much and on most tables the pocket size will still allow the ball to pocket because of a degree of felixibility between the size of the ball and the size of the pocket. If you have greater than like 10 degrees of cut angle and you stroke really hard, it will widen the angle. If you hit a really soft shot with side spin you also have to adjust your aim to more full because of friction induced throw; however, for the average shot, using a pviot point bridge length and BHE will work for everything regardless of how far away, the cut angle etc.

Jaden

p.s. This is assuming as close to a level cue at time of stroke as possible. Swerve and masse effects will change this, sometimes dramatically.

P.P.S I will elevate or lower my bridge hand when putting follow or draw on the ball to reduce the effect of swerve on the shot.

 

[Bob Jewett]

How far can the effective pivot points be from one another for different shots?
I was under the assumption that no matter how hard you stroked and no matter how much english you used the pivot point balances things out.
Thanks.

Since the pivot point gets you to a single line for a particular amount of side spin, and the cue ball does not follow a straight path to the object ball, and the curvature of that path varies with speed, elevation, cloth and ball conditions, there is no way that a single pivot point can work on all shots. The single pivot point argument only works if there is no swerve. There is swerve, and on some shots it amounts to a whole ball.

 

[Jaden]

I can vary from table to table....

The pivot point can vary from table to table and condition to condition, but BHE with few exceptions works on average speed shots, all lengths , all angles.

Jaden

 

[dr_dave]

BHE, FHE, pivot point article

Since we all stroke with the rear hand and keep a stable bridge hand, wouldn't it be counterproductive to have a pivot point, measured from the tip, longer than your bridge hand?

The bridge pivot seems not only to be good for back hand english purposes, but if that bridge pivot equals the pivot point of your cue it becomes a way to ensure that any wavers in your stroke will still pocket balls. I've seen measurements of pivot points of very low deflection cues around 20". This would require a very long bridge in order to make sure you have this pivot point insurance.

FYI, my November '07 BD article has some good illustrations, explanations, and experiments covering this stuff. Check it out. I also have some additional info here:
http://billiards.colostate.edu/threads/cue.html#pivot

Regards,
Dave

 

[Angle Detective]

Thank you everyone for your replies. Dr. Dave, your BD article was one of the things I had read before originally posting. Thanks for the info. Bob, I understand that there's swerve, and I should have been clearer. I wasn't really considering shots that are soft enough to allow swerve to take effect.

And thanks Jaden. It's good to hear from someone who endorses it and puts it into practice. It's a very encouraging thing to find out about.

I have a straight pool video of Efren Reyes playing Jose Garcia where Reyes takes the time to go to his bag and pull out a different cue for only one long shot where the cueball is up table against the rail. Until now I didn't understand this. But I think he may have gone for that cue because the pivot point was closer to the tip than his regular cue. This way he could bridge nearer the pivot point.

 

[Bob Jewett]

... I wasn't really considering shots that are soft enough to allow swerve to take effect. ...

I think there are very few shots with side spin for which swerve does not have an effect. Our conscious mind may arrange to ignore it, but it is there and often is larger than we imagine.