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Ratamon
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02-07-2020, 04:48 AM

One of the best examples of the elbow drop technique is Ronnie O’Sullivan. He drops the elbow on most shots, not just power shots. Don’t think anyone would dare to criticise. To each his own I guess


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02-07-2020, 06:14 AM

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Originally Posted by Patrick Johnson View Post
Lots of power breakers straighten their arm (standing taller to give it room) and move their elbow to develop more power. But it’s not added arm mass that gives them more power - it’s more speed generated by the longer “lever” powered by the shoulder muscles. The longer straightened arm might move the stick faster without seeming to.
For those interested, this is covered in detail in the videos and articles here:

break technique analysis and advice

Dropping the elbow and straightening the arm provides more leverage and activates larger and stronger muscles (in the shoulder) resulting in more cue speed with less apparent effort.

And as Bob points out, CB speed depends only on the cue mass and speed at the incredibly brief moment of tip contact. Here are links to resources that back up this fact:

cue tip contact time

light vs. tight grip effects

stroke acceleration effects

stroke follow through effects

stroke elbow drop effects

cue weight effects

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Dave
  
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02-07-2020, 09:11 AM

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Originally Posted by Ratamon View Post
One of the best examples of the elbow drop technique is Ronnie O’Sullivan. He drops the elbow on most shots, not just power shots. Don’t think anyone would dare to criticise. To each his own I guess. ....
I think with a piston stroke it is impossible not to drop the elbow.

Also, O'Sullivan often raises his elbow at the pause between backstroke and power stroke.


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02-07-2020, 09:42 AM

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Originally Posted by Bob Jewett View Post
I think with a piston stroke it is impossible not to drop the elbow.

Also, O'Sullivan often raises his elbow at the pause between backstroke and power stroke.
Here's a diagram of pendulum vs. piston stroke dynamics. The piston stroke (used by snooker players) has the elbow moving up and down throughout in order to keep the cue level.

pj
chgo

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02-07-2020, 10:54 AM

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Originally Posted by Patrick Johnson View Post
Here's a diagram of pendulum vs. piston stroke dynamics. The piston stroke (used by snooker players) has the elbow moving up and down throughout in order to keep the cue level.Attachment 540765
As always, excellent illustration. FYI, I've added a quote of your post to the pendulum stroke vs. piston stroke resource page for easy future reference.

Also, check out TP B.18 – Pendulum Stroke Cue Tip Trajectory. It has geometry and math to accurately plot the cue tip trajectory for a typical pendulum stroke. The path into the CB is more more level than many people might think.

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Dave
  
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Patrick Johnson
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02-07-2020, 03:15 PM

Quote:
Originally Posted by Patrick Johnson View Post
Here's a diagram of pendulum vs. piston stroke dynamics. The piston stroke (used by snooker players) has the elbow moving up and down throughout in order to keep the cue level.

pj
chgo

Attachment 540765
An interesting difference?

As the diagram shows, with a piston stroke the elbow drops during follow through and, assuming the elbow is above the shoulder as shown, its downward arc takes it farther away from the CB, actually slowing the stroke's forward motion.

I don't know if this is a feature or a flaw (or neither) - just something I noticed...

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02-07-2020, 06:22 PM

Quote:
Originally Posted by Patrick Johnson View Post
Here's a diagram of pendulum vs. piston stroke dynamics. The piston stroke (used by snooker players) has the elbow moving up and down throughout in order to keep the cue level.

pj
chgo

Attachment 540765
The Dell Hill (Ronnie O’Sullivan mentor), diagram would be slightly different. The setup, prior to the backswing, is not level but already on a downward plane. The backswing from there is similar to the pendulum but now arcing higher, because of the start being higher. That creates more space between the grip and the bridge height. In order to get the tip travel as level as possible at contact the whole arm rotating from the shoulder uses the space created and the subsequent arc down and forward puts the cue into a flatter plane than the pendulum fixed axis. The cue stays longer on plane before and after contact. The elbow still folds and the intent is a longer level plane through contact.

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02-07-2020, 06:53 PM

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Originally Posted by Imac007 View Post
The Dell Hill diagram would be slightly different. The setup, prior to the backswing, is not level but already on a downward plane.
That's true for the pendulum stroke too - we hardly ever strike the CB with a truly level cue. The diagram's level cues are idealized concepts.

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02-08-2020, 05:54 AM

Snooker players have that shoulder lower, closer to the level of the cue than pool players, no?

Maybe the pendulum shoulder might be raised somewhat in the diagram.

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02-08-2020, 08:12 AM

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Originally Posted by MitchDAZB View Post
Snooker players have that shoulder lower, closer to the level of the cue than pool players, no?
I think that depends on how close to the cue they have their chin. Many pool players have their chins on the cue too.

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02-08-2020, 01:54 PM

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Originally Posted by Patrick Johnson View Post
I think that depends on how close to the cue they have their chin. Many pool players have their chins on the cue too.

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chgo
Yes, it's interesting to see pool players put the chin on the cue and pendulum stroke, invariably leading to head movement.
  
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02-08-2020, 02:43 PM

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Originally Posted by MitchDAZB View Post
Yes, it's interesting to see pool players put the chin on the cue and pendulum stroke, invariably leading to head movement.
Close is almost as good. Anyway, I think the head would have to be at least several inches, maybe a foot above the cue to have the shoulder as high as the elbow.

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02-19-2020, 09:53 AM

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Originally Posted by Patrick Johnson View Post
Close is almost as good. Anyway, I think the head would have to be at least several inches, maybe a foot above the cue to have the shoulder as high as the elbow.

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chgo
Dell Hill advocates the 4 point stance. The grip, the bridge and chin make three. The chest to cue instruction is his final. His description of the pendulum stroke with the basic 4 point snooker stance is uncomplementary, “like chickens pecking”. The grip hand comes to the chest, rebounding back much like a peck. The effect of that peck over time, is that subconsciously, the body realizes it is being hit. The net result is that the body adjusts, lifting up. If the lift comes before the stroke, the chin ends up off the cue. If the pendulum is used for the forward half of the stroke many players lift up on the forward part of the shot to avoid the body contact. Hill didn’t fight the need for a downward plane, he set it as the norm. That way the head and cue are both up at address. The higher back of swing transition point allows the guarantee of a straight backswing using the bridge to chest wall, a strength of the 4 point method. Once in line at the back, the forward swing needs to stay in the same vertical plane going forward to stay on line. The wall is not used to guide the cue forward. The intent of the forward swing is still to go through straight but not to have the chest impede the stroke going forward. The cue comes down, not the head going up. The room to come down was created by the higher address position. The whole arm can initiate the forward move down and through. One side benefit is that the arm initiates the stroke, not the hand, and it slows down the transition. Since the cue should be on line at the back of the stroke the hand should stay quiet except for any needed pressure applied by a sideways squeeze.

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02-22-2020, 03:33 PM

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Originally Posted by Patrick Johnson View Post
Here’s a possible reason:

Lots of power breakers straighten their arm (standing taller to give it room) and move their elbow to develop more power. But it’s not added arm mass that gives them more power - it’s more speed generated by the longer “lever” powered by the shoulder muscles. The longer straightened arm might move the stick faster without seeming to.

pj
chgo
Isn't the longer lever length a source of additional power with identical tip speed? Just asking. Wouldn't it be the same as calculating torque? Length times Force?

Just speculating the shoulder can't move as fast as the elbow/forearm and the shoulder more or less hinders total speed and not a multiplier.
  
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02-22-2020, 04:05 PM

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Originally Posted by 3kushn View Post
Isn't the longer lever length a source of additional power with identical tip speed? Just asking. Wouldn't it be the same as calculating torque? Length times Force?

Just speculating the shoulder can't move as fast as the elbow/forearm and the shoulder more or less hinders total speed and not a multiplier.
No. Measurements have shown that the flesh of the hand is much, much softer and pliable than the tip. By the time the hand, wrist, forearm, upper arm barely begin to influence the cue stick, the ball is gone. None of this stuff happens instantaneously so you have to take the different times of reaction into consideration.

It is the same for a golf club. Even though the amount of compression for a golf ball is much larger than for a tip/ferrule/shaft/butt during contact, because the speed is much higher, the contact time is only 0.5 milliseconds, or about half the time of tip-to-cue-ball contact. During that time, the bending wave from the club head to the grip does not have time to get to the grip hands. If a laser cut the golf club off at the bottom of the grip just before impact, the impact and shot would not be changed.


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