Johan Ruijsink stroke theory

Imac007

AzB Silver Member
Silver Member
I don't believe the mass of the arm can be brought to bear on the CB because of the flexing of the soft skin of the grip hand. See Dr. Dave's explanation here: https://billiards.colostate.edu/faq/grip/light-vs-tight/

Sorry, I didn't read all of your post, so I might have misunderstood you.

Speaking of it, have you considered adding a "tl;dr" summary paragraph to your long technical posts? They look interesting, but they're too long for me and I'd like having a way to choose which ones to wade into. Who knows, it might even increase your readership...

pj
chgo

Look for poolmanis videos on YouTube. Lately he has 2 videos shooting one handed. The one handed stroke uses the full arm.

https://youtu.be/rkCnCJZmBhg

The momentum he gets isn’t from the short stroke he employs, it can’t achieve a significant velocity. The momentum is generated primarily by the use of mass. The momentum is generated by the forward motion of the arm and even body when he needs even more. Once in motion the contact of the tip on the ball is so brief that there is no pillowing effect. Also the moment at which the pillowing effect would occur would be when transitioning forward, before any forward movement. It would have to be overcome first before any forward movement could happen. Once that initial resistance is overcome, the forward momentum is established, and won’t be undone at the moment of impact.

Fran this is not based on theory but actual use. The Dell Hill videos and explanation tell us what he taught Ronnie O’Sullivan and other World Champions. He is the World Snooker head coach. Learning and understanding progresses in all sports. Evolving often means leaving old ideas behind as new understanding emerges, it’s the hallmark of progress. Nobody is asking anybody to change. Today’s players need to write their own chapters and create new nostalgia for tomorrow’s generations. Carbon fiber means straight shafts forever. Low deflection is another advancement. Advancement in technique also evolves. Sometimes it seems radical like the Fosbury Flop. The use of the whole arm to help drive the cue through is hardly radical unless you are holding onto old concepts.

As Denise McCluggage said “ Change is the only constant, holding on the only sin.“
 
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Patrick Johnson

Fish of the Day
Silver Member
...drive the cue through is hardly radical unless you are holding onto old concepts.
Old concepts like physical reality. Sorry, think I’ll keep that one.

Regurgitating the same wrong assertion doesn’t make it more right, no matter how many words you toss into the salad.

pj
chgo
 

evergruven

AzB Silver Member
Silver Member
I have.
I have come to the conclusion that when the cue ball is frozen or near the rail, it is much tougher to hit accurately ( and control the speed ) without dropping the elbow and have a smooth piston stroke.

agree..I'm still experimenting myself
but I seem to like choking up/using a forward-balanced cue on this shot
but perhaps why has something to do with your observation, joey
 

evergruven

AzB Silver Member
Silver Member
Over the weekend at the Derby City Classic I had the opportunity to talk to Tyler Styer regarding this article. He said Johan's theory of the 'elbow drop' is that dropping the elbow at the time of cue and cue ball contact reduces the stress on all parts of the body involved because the cue gradually stops. Over the period of a long match it makes it easier to stroke fluidly.

Later I discussed this theory with Fred Agnir, a frequent and respected AZ Billiards contributor. Fred added that the elbow drop should be at the exact time of cue and cue ball contact. Fred also added that it is most important to have the forearm perpendicular to the table bed at time of contact.

It was a pleasure to talk with both gentlemen as both were gracious and knowledgeable.

this seems to jive..
 

Bob Jewett

AZB Osmium Member
Gold Member
Silver Member
... The momentum is generated primarily by the use of mass. The momentum is generated by the forward motion of the arm and even body when he needs even more. ...
Mac, you are completely wrong about this. You do not understand the physics/mechanics of what happens during shots. You have been given references -- why don't you read them?

For everyone else.... This discussion is largely irrelevant to learning the game. Thinking about what body parts are moving to get the stick to the right location, angle and speed is guaranteed to screw up the actual action.

As for Johan's theory, I think it is exactly what a lot of top players learned without knowing any theory. If you watch players as diverse as Nick Varner and Allison Fisher you will see that they have two distinct strokes: on soft shots the elbow does not move. On power shots the elbow drops. I have said for some time that the dropping elbow on power shots keeps the arm from hurting. That is my experience and I think it is the basic principle that has subconsciously taught many players to "drop as required."

Again, if you think about this stuff in play you will not be able to play.
 

Imac007

AzB Silver Member
Silver Member
I have no idea of the reasoning behind Johan’s theory or what it states. I too, have engineering physics on my resume. I trust my experience and the fact that I add a lot of mass to my break, not that much more speed. The cue I break with is 16.7 oz., not a club.
 

Bob Jewett

AZB Osmium Member
Gold Member
Silver Member
I have no idea of the reasoning behind Johan’s theory or what it states. I too, have engineering physics on my resume. I trust my experience and the fact that I add a lot of mass to my break, not that much more speed. The cue I break with is 16.7 oz., not a club.
You need to study the references you have already been given. You are mistaken in this matter.
 

Patrick Johnson

Fish of the Day
Silver Member
You are mistaken in this matter.
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
 

Ratamon

AzB Gold Member
Gold Member
Silver Member
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


Sent from my iPhone using Tapatalk
 

dr_dave

Instructional Author
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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

Regards,
Dave
 

Bob Jewett

AZB Osmium Member
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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.
 

Patrick Johnson

Fish of the Day
Silver Member
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

pendulum vs piston.jpg
 

dr_dave

Instructional Author
Gold Member
Silver Member
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.View 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.

Regards,
Dave
 

Patrick Johnson

Fish of the Day
Silver Member
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

View 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...

pj
chgo
 

Imac007

AzB Silver Member
Silver Member
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

View 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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Patrick Johnson

Fish of the Day
Silver Member
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.

pj
chgo
 

MitchDAZB

AzB Silver Member
Silver Member
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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