BHE and low deflection shafts

NaturalEnglish

NaturalEnglish

Banned
I "think" I understand the concepts of BHE. How ball deflection and swerve cancel out when the shaft if bridged at its pivot point.

What happens when BHE is used with a low deflection shaft like the Predator? Wont the ball deflection by minimized but the swerve still be there? Resulting in no cancellation?

Today I did some testing using BHE with a Predator 314-2 on some straight in shots and using about 2 tips of right english. Missed a lot of shots. I switched to a "standard" shaft and used BHE and made more shots....ie the ball went straight.

Can someone please explain BHE and ifit works with a low deflection shaft?

Some cue makers are bragging about their high density (100+ tree ring wood) shafts. Wouldnt these shafts be very stiff and cause more ball deflection? Again...I THINK the concept and reasoning behind BHE is to use a shaft the allows the 2 parameters (ball deflection and swerve) to cancel out. A high density shaft or a low mass front end shaft (ie Predator) will NOT allow those parameters to cancel out.

Enquiring minds wanna know!
 
It doesnt matter what shaft, adjust your bridge so that when you strike right or left of the cue ball, the cue ball go's straight, you can use a diamond and play with the speed until you find what length bridge and how hard to get the desired effects. Likely a low deflection shaft would require a shorter bridge... If your going to use alot of BHE you need to do this with any cue.


SPINDOKTOR
 
NaturalEnglish said:
I "think" I understand the concepts of BHE. How ball deflection and swerve cancel out when the shaft if bridged at its pivot point.
Click to expand...

I think you don't understand the concept. It's not cue ball deflection (squirt) and swerve that cancel out when pivoting at the pivot point. Swerve is ignored in this concept.

Line up for a centerball hit. Now draw a permanent solid line that is the direction the stick is pointing. This would also be the direction the cueball would move if you hit it.

Now leave your bridge hand fixed and swing the back of the cue left and right. Imagine while doing this there is a dotted black line laser beam pointing in the direction the stick is pointing. So as you swing your back hand from the right to the left, the dotted line points to the left of the solid line and then to the right of it. Do this in either direction until the tip is at the miscue point, i.e., maximum english. All the possible dotted line directions form a "V." If you had a no-squirt shaft, these dotted linee are the directions a (generally spinning) cueball would go.

Repeat this for a very short bridge. What happens? The "V" widens. For a long bridge the "V" narrows.

Now start with a short bridge and consider squirt. You have, for that bridge length, a solid center line, and you have a wide "V" of black dotted lines.

Use a red dashed line for the direction the cueball actually goes. Balls hit with left english will squirt to the right, and balls hit with right english will squirt to the left. So with this short bridge, there is a wide V of black dotted lines, and there is a narrower V of red dotted lines.

If you repeat with a slightly longer bridge, both V's narrow. If you keep lengthening the bridge until the red V has narrowed to nothing, then the red "V" will be on top of the solid black line. This is the cue's pivot point. A ball hit with any english pivoting about this point will travel along the solid center line. The 'canceling" is that the squirt is equal and opposite to the stick direction change.

The black dotted V is still there. For a low deflection shart, this all happens at a long pivot point, perhaps behind the joint.

NaturalEnglish said:
What happens when BHE is used with a low deflection shaft like the Predator? Wont the ball deflection by minimized but the swerve still be there? Resulting in no cancellation?

Today I did some testing using BHE with a Predator 314-2 on some straight in shots and using about 2 tips of right english. Missed a lot of shots. I switched to a "standard" shaft and used BHE and made more shots....ie the ball went straight.

Can someone please explain BHE and ifit works with a low deflection shaft?

Some cue makers are bragging about their high density (100+ tree ring wood) shafts. Wouldnt these shafts be very stiff and cause more ball deflection? Again...I THINK the concept and reasoning behind BHE is to use a shaft the allows the 2 parameters (ball deflection and swerve) to cancel out. A high density shaft or a low mass front end shaft (ie Predator) will NOT allow those parameters to cancel out.

Enquiring minds wanna know!
Click to expand...

For conditions where swerve is minimal (hard hit shots and/or cueball close to object ball), BHE will work moderately well provided you bridge near the pivot point. For low-squirt shafts the pivot point is so far back that this is generally not convenient (some low-squirt shaft owners solve this by pivoting about the rear hand)

In any case, swerve is a whole nuther animal--depends on the elevation of our cue, the speed of the hit, and the slickness of the cloth. Back-hand english is out the window once swerve is brought into the mix anyway.
 
Very good post...

Very good post... I was tempted last night to write up some info and post it, as
I saw the confusion about the swerve. I'm glad you posted that followup.
Rep points awarded.
 
great post mike

and yeah colins vid on bhe is awesome, thats when i finally "got it" after watching that video
 
low deflection shafts like predator 314

Different shaft densities and low end mass shafts like the predators will change where the pivot point is. What oyu want to do is find a shaft that has a pivot point close to where you like to have your bridge on average shots.

A predator I have with a 314 shaft, I cut off the end of the shaft at the end of the ferrule( the end of the shaft is hollow with a foam insert) and drilled a new tenon and added a new ferrule and it hits perfectly with a pivot point at about nine-10 inches.
 
The following website claims the pivot point for the 314-2 is 12.5".

http://www.platinumbilliards.com/rating_deflect.php

12.5" is close to my bridge length. Does that mean I can use BHE and compensate for SOME of the cb behavior? What happens when using parallel english with a 314-2 shaft? No compensation or only 1 of the parameters?

Colin says then using BHE the 2 factors being canceled are "direction of the cb due to the direction of the cue" and the "squirt". I assumed the first factor was swerve. I understand now that is isnt. Is there a better name for it other than "direction of the cb due to the direction of the cue"?
 
You forgot to post the website link...

EDIT: OOPS, I missed the link, sorry... Or you corrected the post...

You forgot to post the website link... And, I suspect that the word "direction" should be
replaced with "deflection" in a couple (but not all) cases in the quote above...
 
Great post.

A month or two ago when the Z2 came in for my playing cue, I felt so awkward not adjusting for squirt... and finding that the ball was swerving on longer/slow shots (or any shot with a greater spin/speed ratio).

A day or two after getting the shaft, I played sjm some 14.1 and broke. I put some right english to try and come two rails back near the head corner pocket... but the cueball swerved and I barely clipped the rack! Only one ball (if that) from the rack was driven to a rail, and the break was a foul. All because the cueball swerved and clipped the rack a lot thinner than I had intended!
 
NaturalEnglish said:
The following website claims the pivot point for the 314-2 is 12.5".

http://www.platinumbilliards.com/rating_deflect.php

12.5" is close to my bridge length. Does that mean I can use BHE and compensate for SOME of the cb behavior? What happens when using parallel english with a 314-2 shaft? No compensation or only 1 of the parameters?

Colin says then using BHE the 2 factors being canceled are "direction of the cb due to the direction of the cue" and the "squirt". I assumed the first factor was swerve. I understand now that is isnt. Is there a better name for it other than "direction of the cb due to the direction of the cue"?
Click to expand...

I believe that what is happening that allows for BHE and pivot points to work is the bowing of the shaft in a specific direction.

If you are on the correct aim line aiming for center ball and you pivot the cue off to the side for the english you want (BHE), when the cue hits the cue ball, the majority of the mass of the CB is off to one side so that when the shaft bends from the mass of the CB imparting pressure on the shaft it bends in a specific direction so that when the CB is leaving the tip of the Cue, the end of the shaft is pointing back toward the original point of aim.


Let me see if I can illustrate this.

CueTable Help



In this diagram the black line represents the original center shot line of teh cue stick. The yellow line represents the pivoted left english and the bow of teh shaft as it pushes forward on the CB.

As you can see as the shaft bends toward the direction of the center of mass of the CB, it ends up facing on more of a direct line with the original aimline. Depending on how flimsy the shaft is and how much counter mass is in the tip of teh shaft and where your bridge (stabalizing point) is, there will be a specific point of stabalizing point where the amount of bow in the shaft is exactly how much is needed for the shaft to be pointing in exactly the right direction when the CB leaves the tip sending it exactly where you need.

A friend of mine told me that he couldn't use BHE with his Z shaft and 314-2 and I showed him that I could by bridging farther back. In other words, if you have a straight stroke and know how to use BHE, a low deflection shaft will lower your consistency because it forces you to use a longer bridge or to use manual adjustment for english.

What you should do is find or have a shaft made that has a pivot point where your bridge is most confortable if you want to use BHE to adjust for squirt and throw.
 
Thanks for putting my video up Jal, I was a bit late finding this thread.

I maybe repeating some of the other responses here, but wanted to raise a couple of points in response to the original question.

When using low squirt cues, sometime it necessitates using a very long bridge to make shots using BHE. Particularly with slow shots, on slow cloths (extra swerve) and when using OE (because you actually need to contact the object ball a little fuller).

For low speed shots with english it probably isn't a bad idea to use a higher deflection cue, so that a normal bridge length works quite well.

However, low squirt cues have less variation, so are more predictable, particularly when hitting firm and power shots.

I think a low squirt cue is better all round for BHE play, but I wouldn't go out looking for the lowest squirt cues.

When 12.5" is mentioned for the pivot point, this is not taking into account swerve, which has to be allowed for on slower shots. So on 12.5" pivot point on a low speed shot with CB a four feet from the OB, you may actually need to pivot at 25" for all effects to cancel out so that the CB strike the OB at the same point as the original aim.

While it's all pretty complex, with enough work you can get to learn the compensations for most shots pretty well.

Colin
 
NaturalEnglish said:
The following website claims the pivot point for the 314-2 is 12.5".

http://www.platinumbilliards.com/rating_deflect.php

12.5" is close to my bridge length. Does that mean I can use BHE and compensate for SOME of the cb behavior? What happens when using parallel english with a 314-2 shaft? No compensation or only 1 of the parameters?

Colin says then using BHE the 2 factors being canceled are "direction of the cb due to the direction of the cue" and the "squirt". I assumed the first factor was swerve. I understand now that is isnt. Is there a better name for it other than "direction of the cb due to the direction of the cue"?
Click to expand...

Natural English,

Maybe this formula will make it clearer.

When BHE achieve the same CB-OB contact as the original aim, the following must be true:

Original Aim = Pivoted Aim - Squirt + Swerve

Swerve is negligable when speed of shot is high and when OB and CB are close together.

Squirt increases with a longer bridge length and probably with higher speeds (though it's hard to know the magnitude of this because the role of swerve is significant).

Increased Pivot leads to Increased Squirt. (They seem to neatly cancel out, hence the magic of the aim and pivot method).

btw: You might call Orginal Aim the Original Cue Direction and the Pivoted Aim the Pivoted Cue Direction.

Colin
 
Thanks for the input Colin...I was hoping you would chime in on this thread. Its complex stuff...and I think you have spend more time trying to figure it out than most. Still confusing...but I like your mathematical formula to summarize it.

Its starting to sound like golf. Ok...this is a low speed cut...so I go to my cue bag and take out the cue best suited for that shot. Whats wrong with that? Sounds like an job oportunity for cue caddies. In the corner your caddy suggests you play the #4 cue with a little outside English and medium ball speed. haha...maybe someday we carry 10 cues to a match....no I mean our caddy cares our cue bag to the match!
 
mikepage said:
In any case, swerve is a whole nuther animal--depends on the elevation of our cue, the speed of the hit, and the slickness of the cloth. Back-hand english is out the window once swerve is brought into the mix anyway.
Click to expand...

That was a very well explained post Mike. The reason I made my video was because it was so hard to try to explain BHE in a way that people could follow.

I do want to make one comment regarding Swerve and BHE though:

Most players avoid playing swerve shots like the plague, for good reason, but through practice and tuning their intuition, they get to a level whereby they can acquire reasonable accuracy when having to play shots that will swerve significantly.

I figure that using BHE for swerving shots provides a good baseline to develop this sense of estimation / intuition.

For example, when I am playing a 90 degree cut back shot rail first over the length of the table, there will be about 1/4" of swerve at firm speed if I am shooting from the baulk area. So I make my original alignment to miss the intended aim by that amount.

If by practice I can make a reasonable estimation of the amounts of swerve involved in various shots, I can hone my compensations. The beauty of BHE is that it can tell you how much certain shots do swerve, providing more data for future compensations.

Whereas, when using parallel type aiming, it is hard to know the relative deviations of squirt and swerve, making it harder to develop a compensatory system.

Colin
 
NaturalEnglish said:
The following website claims the pivot point for the 314-2 is 12.5".

http://www.platinumbilliards.com/rating_deflect.php...
Click to expand...
Colin employs a more sophisticated concept of a swerve compensating pivot point. But every cue has an intrinsic pivot point which does not depend on swerve. By intrinsic, I mean the following, which is essentially what Mike Page described: if you line up for a center ball hit, then pivot the cue about its intrinsic pivot point in order to apply english, the cueball will nevertheless take off in the same direction as if you were still aiming centerball (but with spin this time which will cause it to follow a curved path unless the cue was perfectly level). Tests by Platinum Billiards (and theory) say that its location on the cue changes very, very little with shot speed.

I bring it up because after 643,789,234,853,271 posts on squirt on various billiard forums over the years, it hasn't been resolved if the low squirt cues have intrinsic pivot points in the 12-14" range, or the 30-50" range! On the one hand, you have very technically knowledgeable people, such as Mike Page (and Ron Shepard who wrote a paper on the subject), who say it's up there in the high range (30-50"). On the other hand, Platinum, and Predator themselves, report the lower figures. You would think that Predator, whose business is low squirt cues, would love to offer numbers in the high range, as they represent very low squirt, but they don't.

Who's right? Maybe before the end of the century we'll know.

Jim
 
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Jal said:
Colin employs a more sophisticated concept of a swerve compensating pivot point. But every cue has an intrinsic pivot point which does not depend on swerve. By intrinsic, I mean the following, which is essentially what Mike Page described: if you line up for a center ball hit, then pivot the cue about its intrinsic pivot point in order to apply english, the cueball will nevertheless take off in the same direction as if you were still aiming centerball (but with spin this time which will cause it to follow a curved path unless the cue was perfectly level). Tests by Platinum Billiards (and theory) say that its location on the cue changes very, very little with shot speed.

I bring it up because after 643,789,234,853,271 posts on squirt on various billiard forums over the years, it hasn't been resolved if the low squirt cues have intrinsic pivot points in the 12-14" range, or the 30-50" range! On the one hand, you have very technically knowledgeable people, such as Mike Page (and Ron Shepard who wrote a paper on the subject), who say it's up there in the high range (30-50"). On the other hand, Platinum, and Predator themselves, report the lower figures. You would think that Predator, whose business is low squirt cues, would love to offer numbers in the high range, as they represent very low squirt, but they don't.

Who's right? Maybe before the end of the century we'll know.

Jim
Click to expand...

Jim,
It is good to clarify that there is this constant pivot point, though I would like to know how much this pivot point varies with speed and offset. I'm sure it must vary somewhat, but we'll need some accurate testing methods to ascertain the variation.

Regarding the higher 30-50" pivot point estimates, I just cannot believe we are measuring the same things. My hundreds of hours of testing closely correlate to Platinum's test results.

I'm not sure what has caused of this difference of opinion regarding a correct measure of pivot points.:confused:

Colin
 
Colin Colenso said:
Jim,
It is good to clarify that there is this constant pivot point, though I would like to know how much this pivot point varies with speed and offset. I'm sure it must vary somewhat, but we'll need some accurate testing methods to ascertain the variation.
Click to expand...
Hi Colin. With regard to how squirt varies with shot speed, there is a post by Steve Titus of Platinum Billiards here, (see about 8/10'ths of the way down the page). He says that there is an increase of 0.2-0.3% per mile per hour over the range of shot speeds from 9 to 21 mph. This sounds believable to me, because after diddling with the numbers myself, I got an increase of about 0.75-1.0% per mph (they're in the ballpark anyway, and my theory was barebones). More importantly, Ron Shepard also concludes in his paper that there should only be a minor dependency on speed. I think this is backed up by an intuitive consideration of what goes on during impact, but I won't go into that now.

As far as the location of the pivot point, his theory also shows only a minor dependency on tip offset. It moves slightly farther from the tip with increasing offset (english). In his example, for a ball/endmass ratio of 40, it goes from 19" at an offset (b/R) of 1/4, to 21.5" at an offset (b/R) of 1/2. Of course, I know you think there might be more going on then the endmass theory incorporates, but there it is.

Colin Colenso said:
Regarding the higher 30-50" pivot point estimates, I just cannot believe we are measuring the same things. My hundreds of hours of testing closely correlate to Platinum's test results.

I'm not sure what has caused of this difference of opinion regarding a correct measure of pivot points.:confused:
Click to expand...
It's crazy isn't it! But at least it makes for a good mystery.

I can see some potential problems with the aim-and-pivot test if people judge there to be a full hit when the cueball stops dead and spins in place. Because of throw, and even more so from post-impact swerve, I believe the cueball should move something like 4" over to the side after impact (depending on speed, offset and cue elevation of course). But from the numbers I get, this is not enough to explain the gross discrepancy?

Platinum's robot has, well, a robotic-like grip on the cue (at least it did at one time), which can increase the mass that the cueball "sees". But I don't think this offers any real explanation for their numbers if the 30-50" crowd is right.

If I had a Predator shaft, I would use aim-and-pivot with a wetted contact point on the object ball to all but eliminate throw, and pay zero attention to what the cueball does after impact. The criteria for a full hit would be having the object ball go straight, and nothing else. But alas, I don't.

Perhaps your collaberation with Dr. Dave, if that's still in the works, will take on this conundrum. It is interesting, isn't it.

Jim
 
Have you watched some of Joe Tucker's laser trainer videos?

http://www.youtube.com/watch?v=hwVBh73s9js&feature=PlayList&p=80C27B389E4BF9A1&index=5

With his laser gadget he can be certain of aim and then he uses BHE on some straight in shots. The cb stops dead inline and spins in place. He doesnt say what shaft he is using. It was his videos that got me thinking about BHE and pivot point again. When I have tried it with my predator shaft...BHE doesnt seem to work like Joe's video. If the cb stops and spins in place, the ob misses the pocket. If I hit the pocket I get some cb side drift. Of course it could be my aim inconsistency? With the laser trainer, it looks like the cue is just slding in a groove...ie there really isnt a pivot "point" like a hand bridge would have. Does that effect the results also?
 
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