Robert,
Your statements make a lot of sense although 36% seems like a phenomenal amount of transfer of spin.
What do you think is the maximum percentage of spin transfer is possible on brand new Simonis cloth on pocket billiard tables?
John Brumback visits Betmore's Basement
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Robert,
Your statements make a lot of sense although 36% seems like a phenomenal amount of transfer of spin.
What do you think is the maximum percentage of spin transfer is possible on brand new Simonis cloth on pocket billiard tables?
Willie, thanks for the write-ups. You are very good with words.
EDIT: Just for reference showing JB's closed bridge. (Taken from the oDream or Nightmare thread, courtesy of Rick S.)
Can you please elaborate on this? What is to be considered a "good" bridge (open or closed)? What are the common "inadequacies"?
EDIT: Just for reference showing JB's closed bridge. (Taken from the oDream or Nightmare thread, courtesy of Rick S.)
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J-man,
Take a look at the middle finger and little finger on John's left hand. Note that they are spread as far apart as possible (most people could not get them quite that far apart - the reason for John's stretching exercises; you can over time stretch those fingers farther and farther apart - it's only a very small increase, but provides a noticeable increase and improvement in stability).
Once the fingers are spread that far apart, they also have some natural elastic tendency to try to close back together. That natural elasticity "grabs" the cloth slightly, giving a subtle but noticeable increase and improvement in stability.
He also has improved the flexibility of his index finger, allowing it to contact the top of the middle finger - something difficult for many amateurs.
As far as the open bridge; John's is very similar, except in this case it is the index finger and little finger that are maximally spread - an even wider span than with the closed bridge. John also keeps his thumb higher than many amateurs, making the "V" with the interphalangeal joint of the thumb pressed against the metacarpal/phalangeal joint at the base of the index finger (not lower against the side of the index finger itself).
Both John and Jeanette Lee seem to favor a more natural positioning of the open bridge hand as a natural extension in the direction of the left arm (not pointing straight along the shot line as favored by some snooker professionals; but rather pointing along the line of the left forearm). They both feel that the resulting slight angling of the bridge hand across the shot line allows the cue to slide through the "V" without making contact with the fleshy bulge made by the thumb pressing into the soft tissue of the medial hand. The more the open bridge hand is angled forward towards the shot line, the more this fleshy bulge moves toward a position where it would touch the cue shaft. Its different for every person's hand, but you catch the drift.
Much of this will be discussed in detail in Mark Wilson's upcoming book (hopefully available by the end of this year) - an extremely detailed analysis of all of these very small details, that can yield very small improvements in any player's game.
Clear as mud??? This is why hands-on instruction is always better, a picture is worth a thousand words.
Surprisingly, the max is still 36% LOL. You're asking the wrong question, but I know what you mean
Max spin transfer percentage is the same on all equipment and conditions because it's the amount that is transferred when there is no slipping between the CB and OB. It's related to the moment of inertia (resistance to change in rotation) for solid spheres. Hollow shells like ping pong balls have different max percentages.
The following are some of the reasons that the max can seem different with different equipment:
- Ball-ball friction and shot speed can change how quickly the percentage decreases from max as you increase CB spin. That's because you start slipping against the OB sooner at smaller spin amounts when the balls are cleaner and/or you shoot faster.
- Lower ball-cushion friction can make the same amount of spin appear to be less because it doesn't change the output angle as much.
- Higher ball-table friction (esp. nappy cloth) can make the same amount of spin appear to be less because more spin is worn off on the way to the cushion.
Since speed reduces the transfer percentage, why do bankers frequently fire in long twisting banks at high speed? Shooting slower would transfer more spin, but it would wear off before it gets to the cushion. Good bankers have a feel for the best tradeoff at various distances.
Robert
Hey there.I'm not big into the "physics" part of pool,But you did explain part of what I teach.In that, If you put alot of english on the cball, you won't get much transfer to the oject ball. I could show you some shots to where I can transfer alot to the object ball without spinning the cue ball at all. I have often wanted to use a high speed camera to catch this. Well,thought I would just throw this In here.Not trying to sound like a smart###. You sound to smart for me to argue with.lol Thanks,John Brumback
Surprisingly, the max is still 36% LOL. You're asking the wrong question, but I know what you mean
Max spin transfer percentage is the same on all equipment and conditions because it's the amount that is transferred when there is no slipping between the CB and OB. It's related to the moment of inertia (resistance to change in rotation) for solid spheres. Hollow shells like ping pong balls have different max percentages.
The following are some of the reasons that the max can seem different with different equipment:
Clean balls and new cloth are the worst combination for spinning OBs off of cushions (dirty balls and sticky cushions on napless bedcloth would be the ideal conditions I mentioned where you can retain that 36% for higher CB spins before slipping).
- Ball-ball friction and shot speed can change how quickly the percentage decreases from max as you increase CB spin. That's because you start slipping against the OB sooner at smaller spin amounts when the balls are cleaner and/or you shoot faster.
- Lower ball-cushion friction can make the same amount of spin appear to be less because it doesn't change the output angle as much.
- Higher ball-table friction (esp. nappy cloth) can make the same amount of spin appear to be less because more spin is worn off on the way to the cushion.
Since speed reduces the transfer percentage, why do bankers frequently fire in long twisting banks at high speed? Shooting slower would transfer more spin, but it would wear off before it gets to the cushion. Good bankers have a feel for the best tradeoff at various distances.
Robert
You're right Robert. I asked the wrong question but you understood what I was looking for. Thanks!
Robert, in your opinion, which of the four hits below on the object ball will transfer the most amount of spin:
Full Ball
3/4 Ball
1/2 Ball
1/4 Ball
Thanks,
JoeyA
You can definitely spin the object ball without applying sidespin to the cue ball (stun shots around 5/8 to 1/2 ball are easiest but others are possible). That's because from a physics perspective, a cue ball with no sidespin acts like inside english during cut shots.
However, even though you may start the shot with a dead cue ball, the cue ball will pick up some sidespin during the collision in the same way the object ball does. If it didn't, it would violate conservation of angular momentum, and we'd be in position to receive Nobel Prizes if we could clearly demonstrate something like that!
Btw, CueTable is a great resource for diagramming shots to discuss them online. If there is a specific position you have in mind, maybe you could try drawing it to make talking about it easier?
Robert
p.s. I don't have a high-speed camera, but "Dr. Dave" Alciatore does. Maybe you could arrange a session to explore some of your favorite shots more closely. I'm sure we'd all enjoy watching a champion like you making them in super slow motion.
The answer to that is easy: it depends! You're full of good questions, Joey
When shooting the hits you mentioned with zero CB english, 1/2 ball will transfer the most for stun shots, and 1/4 ball will transfer the most when using max follow or draw. When using english (which you didn't mention), things get more complicated.
A useful way to think about OB spin transfer is to think about OB throw since they're intrinsically tied together. Both are the result of friction between the balls during collision. Whatever conditions give you the most OB throw will give you the most OB spin transfer, and whenever you minimize throw you'll minimize transferred spin.
Unfortunately, max throw happens at different hits for different CB spins and speeds. Bob Jewett, Dr. Dave and others have written about this at length elsewhere, but here's a brief summary of the ideas from the perspective of spin transfer:
- Every hit has a "natural" throw-canceling amount of outside english that causes the CB to roll against the OB without throwing it offline or transferring any sidespin to it. For a full hit, the natural english is no english. For a very thin cut it's about 75% of max english.
- Any CB outside english greater than the natural amount will increase the cut angle and transfer inside english to the OB. (e.g. overspinning right CB english causes left OB english).
- Any CB english less than the natural amount (less outside, zero, or any inside) will decrease the cut angle and transfer outside english to the CB. (e.g. any CB english from left inside up to underspinning right causes right OB english).
- Spin transfer increases as CB english moves away from the natural amount (either more or less) up to the max point where the balls stop adhering and start slipping against each other. After that, it starts decreasing.
- In general for a particular hit and english, follow and draw reduce sidespin transfer, whereas stun (sliding into the OB without follow or draw) maximizes it.
That's enough rambling for now
Let me know if you have any further questions.Robert
I got to figure out a way to get myself along with Archer and Varner to the basement very soon as we will be going right through there.
MC,
I'll leave the light on.