For the Science Guys #2

lfigueroa

lfigueroa

AzB Silver Member
Silver Member
Same player, diffrent shot, diffrent claim:

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"...if you want the ob ball to "break" to the pocket on the initial straight back using the reverse eng needed to carry the cue ball around the table, contrary to what most players think, the more reverse you use the more the ob ball will break rather than stiff off of the rail and run short. This is one of the great secrets of bank pool, maximum rev will give you a completely opposite effect of what you have come to expect."

So once again for the science guys: will more reverse english increase the angle of the OB off the rail rather than reduce it?

Lou Figueroa
 
lfigueroa said:
Same player, diffrent shot, diffrent claim:

CueTable Help



"...if you want the ob ball to "break" to the pocket on the initial straight back using the reverse eng needed to carry the cue ball around the table, contrary to what most players think, the more reverse you use the more the ob ball will break rather than stiff off of the rail and run short. This is one of the great secrets of bank pool, maximum rev will give you a completely opposite effect of what you have come to expect."

So once again for the science guys: will more reverse english increase the angle of the OB off the rail rather than reduce it?

Lou Figueroa
Click to expand...

Given the first claim I'm sure it's only accidental, but he's right about this one, at least in theory - more spin does generally mean less throw and less transferred spin, both of which help your bank. But it doesn't take much, especially when you're cutting the ball, so if you're already spinning the ball adding more spin probably won't make much difference.

I'm going to have to give him 1/2 point for at least getting the principle right.

pj
chgo
 
I'll take a stab at this, and while I am an engineer (electrical), I am not Dr. Dave, Bob Jewett, Mike Page or Colin Colenso (all of whom I respect very much).

I don't know what he is meaning when he says "reverse english," so to avoid confusion and conflict, I will use "left" and "right."

Left english will speed up the cue ball and flatten the angle as it leaves the first rail. Right english will slow down the cue ball and steepen the angle as it leaves the first rail.
 
I'm gonna have to take your word for it Lou since I don't play the game. I just tried the shot on my 3C table. The hit that takes the CB to 1 makes the shot. Can't explain it. Just have to trust your reason.
But, I can't help myself but say your 3rd rail doesn't connect to the corner. Did you forget your 3rd rail return adjustment?? :smile:

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Patrick Johnson said:
Given the first claim I'm sure it's only accidental, but he's right about this one, at least in theory - more spin does generally mean less throw and less transferred spin, both of which help your bank. But it doesn't take much, especially when you're cutting the ball, so if you're already spinning the ball adding more spin probably won't make much difference.

I'm going to have to give him 1/2 point for at least getting the principle right.

pj
chgo
Click to expand...


I though maybe a .25.

Actually, my theory was that because he's talking about max reverse (speed, offset?) he might be seeing the results of additional squirt. But like I said, I'm not a science guy.

Lou Figueroa
 
3kushn said:
I'm gonna have to take your word for it Lou since I don't play the game. I just tried the shot on my 3C table. The hit that takes the CB to 1 makes the shot. Can't explain it. Just have to trust your reason.
But, I can't help myself but say your 3rd rail doesn't connect to the corner. Did you forget your 3rd rail return adjustment?? :smile:

CueTable Help

Click to expand...


I think you're absolutely right. I was just trying to quickly copy the layout.

Lou Figueroa
 
Some of you guys are concentrating on the cueball path after it leaves the OB. But the question is: Is there a point at which the OB angle widens off the rail due to extreme inside english? And if so, what causes that to happen?

Doc
 
gulfportdoc said:
Some of you guys are concentrating on the cueball path after it leaves the OB. But the question is: Is there a point at which the OB angle widens off the rail due to extreme inside english? And if so, what causes that to happen?

Doc
Click to expand...

The hit shown in the diagram is about a half ball, which is where you'd get maximum collision-induced throw and OB spin (the two things making the bank angle steeper). Adding any inside spin reduces throw and OB spin (widening the bank angle), so it doesn't need to be extreme. I think maximum bank angle widening is reached with very little added spin.

pj
chgo

P.S. I'm assuming that you manage to hit the same OB contact point each time - i.e., squirt doesn't widen the cut angle.
 
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lfigueroa said:
I though maybe a .25.

Actually, my theory was that because he's talking about max reverse (speed, offset?) he might be seeing the results of additional squirt. But like I said, I'm not a science guy.

Lou Figueroa
Click to expand...

That was my first guess, too. Maximum left english means squirt to the right, which means likely cutting the 12 a bit thinner than the shooter might realize. The "widening" of the angle is largely imagined, I think, since there's no way the 12 will be spinning the right direction to make this happen. The guy thinks he's cutting the ball into one spot on the rail, which would require the OB to spin wide off the rail in order to make the shot. He then makes the shot by overcutting it, actually missing the spot on the rail he thinks he's hitting, but he sees that he made the shot and so he thinks he spun the OB off the rail.

-Andrew
 
Andrew Manning said:
That was my first guess, too. Maximum left english means squirt to the right, which means likely cutting the 12 a bit thinner than the shooter might realize. The "widening" of the angle is largely imagined, I think, since there's no way the 12 will be spinning the right direction to make this happen. The guy thinks he's cutting the ball into one spot on the rail, which would require the OB to spin wide off the rail in order to make the shot. He then makes the shot by overcutting it, actually missing the spot on the rail he thinks he's hitting, but he sees that he made the shot and so he thinks he spun the OB off the rail.

-Andrew
Click to expand...


Yeah, I think squirt is the culprit.

For those that might not agree, try this:

CueTable Help



The balls on the rail are just a smidge more than a ball's width apart. Shoot the two with something like the max english we're talking about, without hitting either of the balls on the rail, on the way in. It's not so easy.

Lou Figueroa
 
lfigueroa said:
Yeah, I think squirt is the culprit.

For those that might not agree, try this:

CueTable Help



The balls on the rail are just a smidge more than a ball's width apart. Shoot the two with something like the max english we're talking about, without hitting either of the balls on the rail, on the way in. It's not so easy.

Lou Figueroa
Click to expand...

But it's a helluva a way to practice aiming your OB control. 5 stars.
 
lfigueroa said:
Yeah, I think squirt is the culprit.

For those that might not agree, try this:

CueTable Help



The balls on the rail are just a smidge more than a ball's width apart. Shoot the two with something like the max english we're talking about, without hitting either of the balls on the rail, on the way in. It's not so easy.

Lou Figueroa
Click to expand...

I suggest trying this:

CueTable Help



pj
chgo
 
lfigueroa said:
So once again for the science guys: will more reverse english increase the angle of the OB off the rail rather than reduce it?

Lou Figueroa
Click to expand...

Hi Lou,

I just came across this while ahrciving layouts.

At the speed as shown, the angle should be reduced by two factors :
1, cue ball induced spin, using inside english will add more effects (the shot on page 2 uses similar idea)
2, cushion rubber rebound

I am not a science person, but I can't imagine how the angle can be increased by the inside english... Maybe I am missing something here?

CueTable Help

 
cuetable said:
Hi Lou,

I just came across this while ahrciving layouts.

At the speed as shown, the angle should be reduced by two factors :
1, cue ball induced spin, using inside english will add more effects (the shot on page 2 uses similar idea)
2, cushion rubber rebound

I am not a science person, but I can't imagine how the angle can be increased by the inside english... Maybe I am missing something here?

CueTable Help

Click to expand...
Actually, I am the one that drew this diagram, and you guys are all reading way too much scientific analysis into my very quick sketch of the cue ball and object ball paths here. All I was doing was showing the possibility of scratching when the shot is struck with loaded left english (left for the inside/outside geeks), which nicely runs the cue ball three rails around the table even when shooting this bank at "pocket speed". The sketch was done way too quickly for use in scientific analysis or diamond tracking systems!

Geeeezzzz -----> Lou needs to learn how to draw his own friggin diagrams...
 
lfigueroa said:
...Actually, my theory was that because he's talking about max reverse (speed, offset?) he might be seeing the results of additional squirt. But like I said, I'm not a science guy.

Lou Figueroa
Click to expand...
I think Patrick explained it if you assume the object ball is contacting the cushion at the same spot and at about the same speed in either situation: with and without inside english on the cueball. In that case, squirt and throw are compensated for. Otherwise, I don't think it's a fair comparison - obviously the OB will come off wider if its approach to the cushion is shallower (all else equal).

What's important for the rebound angle is its sidespin/speed ratio and how much topspin it's picked up along the way. If its speed is the same in both cases, that eliminates the topspin variable, leaving sidespin. As Patrick implied (I pretty sure), the object ball acquires the largest sidespin/speed ratio when maximum throw occurs. For something like a stun shot without english, this happens at about a half-ball cut (less if struck hard or the balls are unusually slick), which is roughly what is shown in the original diagram. Adding loads of inside only reduces throw, and significantly so, and therefore the OB's sidespin/speed ratio. You should expect it to rebound wider from this alone...even with perfect squirt/throw comp.

Jim
 
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