Why do Teachers insist on the Pendulum?

[Patrick Johnson]

I thought the elbow had to stay pinned. I thought instructors put an item on the forearm to make it stay there during the stroke.

Some do; some don't. As has been said multiple times here, dropping the elbow after contact doesn't change the shot - but how do you teach that? Keeping the elbow still throughout the shot is just the easiest way to ensure there will be no dropping before contact.

pj
chgo

 

[Bobkitty]

He dropped what maybe 3 inches....wow I guess he uses a J stroke. <sarcasm>

cy.

On the second shot, his elbow dropped to his waist and not 3". I was thinking this was the ultimate "piston" stroke. So different from Oyster. Confused here.

 

[Tony_in_MD]

Again, look at it in slow motion, is the drop before or after CB contact?

On the second shot, his elbow dropped to his waist and not 3". I was thinking this was the ultimate "piston" stroke. So different from Oyster. Confused here.

 

[Bobkitty]

Again, look at it in slow motion, is the drop before or after CB contact?

So, if the cue stick has the forearm vertical with the tip at impact, everyone must have a pendulum stroke because when the tip hits the CB, the elbow is not dropping? Is this correct? So Massey's super draw stroke in the Oyster video you provided is a pendulum stroke? His elbow doesn't drop until after impact. Can you show me a video of someone using a "piston" stroke where the elbow drops before impact? Thanks.

 

[Bob Jewett]

So, if the cue stick has the forearm vertical with the tip at impact, everyone must have a pendulum stroke because when the tip hits the CB, the elbow is not dropping? Is this correct? ...

No, it's not correct. Simple mechanics shows that the elbow could be moving in spite of verticality at the instant of contact.

As for the piston stroke, beginning with the tip at the cue ball just prior to the backswing, the elbow must then drop and rise and drop as the player executes the stroke. This is also very simple mechanics. Perhaps you need to spend some time drawing diagrams or working with simple models.

 

[Bobkitty]

No, it's not correct. Simple mechanics shows that the elbow could be moving in spite of verticality at the instant of contact.

As for the piston stroke, beginning with the tip at the cue ball just prior to the backswing, the elbow must then drop and rise and drop as the player executes the stroke. This is also very simple mechanics. Perhaps you need to spend some time drawing diagrams or working with simple models.

Okay. So O'Sullivan has a pendulum stroke on his forceful shots. Thanks.

 

[Bob Jewett]

Okay. So O'Sullivan has a pendulum stroke on his forceful shots. Thanks.

That's certainly not a reasonable conclusion from what I said.

 

[Tony_in_MD]

Bustamante

https://www.youtube.com/watch?v=XoEFwSUkD18

Something else for you to ponder. If this is the pool stroke that provides the most action on a CB, wouldn't you think LOTS of other pros would have copied it?

Remember, if they don't cash they don't eat.

So, if the cue stick has the forearm vertical with the tip at impact, everyone must have a pendulum stroke because when the tip hits the CB, the elbow is not dropping? Is this correct? So Massey's super draw stroke in the Oyster video you provided is a pendulum stroke? His elbow doesn't drop until after impact. Can you show me a video of someone using a "piston" stroke where the elbow drops before impact? Thanks.

 

[Bobkitty]

That's certainly not a reasonable conclusion from what I said.

I'm done here. I have always thought that if the elbow dropped "after the cue stick hit the CB" was NOT a pendulum stroke. But now, you are writing that if the elbow stays constant on CB contact and moves downward after that instant, it is still a pendulum stroke. I give up.

 

[garczar]

I'm done here. I have always thought that if the elbow dropped "after the cue stick hit the CB" was NOT a pendulum stroke. But now, you are writing that if the elbow stays constant on CB contact and moves downward after that instant, it is still a pendulum stroke. I give up.

Seriously?? Done-done??? Whewwwww.

 

[Bobkitty]

………………………..…………...

 

[AtLarge]

I'm done here. I have always thought that if the elbow dropped "after the cue stick hit the CB" was NOT a pendulum stroke. But now, you are writing that if the elbow stays constant on CB contact and moves downward after that instant, it is still a pendulum stroke. I give up.

Pendulum, piston, and "J" strokes, per Dr. Dave: https://www.billiards.colostate.edu/FAQ/stroke/pendulum-piston/

 

[Pidge]

The simple answer is that it's generally easier for students to get their head around as they have to concentrate on fewer moving parts.

 

[Patrick Johnson]

To help me (and hopefully others) visualize things, here's a diagrammed comparison of the arm/stick motions for "idealized" pendulum and piston strokes.

The pendulum stroke keeps the elbow still and lets the cue's butt rise and fall. The piston stroke keeps the cue level by dropping and raising the elbow in a coordinated motion.

In both cases the forearm is vertical at address and at tip/ball contact, the backswing is 45 degrees (~10 inches, the length of the bridge) and the follow through is 30 degrees (~6 inches, where the tip hits the cloth with the pendulum stroke).

The physical shot results are practically indentical - the tip contacts the CB at the same point with the cue traveling horizontally. The only significant difference in tip motion is well after contact, when the pendulum stroke's tip dips sharply to the cloth at the end of the follow through.

pj
chgo

 

[Bobkitty]

The pendulum stroke keeps the elbow still and lets the cue's butt rise and fall. The piston stroke keeps the cue level by dropping and raising the elbow in a coordinated motion.

In both cases the forearm is vertical at address and at tip/ball contact, the backswing is 45 degrees (~10 inches, the length of the bridge) and the follow through is 30 degrees (~6 inches, where the tip hits the cloth with the pendulum stroke).


chgo

Thanks for the diagrams. What is the stroke if the cue goes back in the pendulum fashion and on the forward swing at contact the elbow and upper arm moves down to give a nice long parallel to the table follow through? Is that a pendulum stroke?

 

[Patrick Johnson]

Thanks for the diagrams. What is the stroke if the cue goes back in the pendulum fashion and on the forward swing at contact the elbow and upper arm moves down to give a nice long parallel to the table follow through? Is that a pendulum stroke?

I think that's what's called a "J" stroke - it qualifies as a kind of pendulum stroke because the elbow doesn't drop until after contact.

pj
chgo

 

[Dan White]

Thanks for the diagrams. What is the stroke if the cue goes back in the pendulum fashion and on the forward swing at contact the elbow and upper arm moves down to give a nice long parallel to the table follow through? Is that a pendulum stroke?

Look at the link to Dr. Dave's site and you'll see a discussion of the J stroke, which is what you are asking about.

 

[bbb]

Thanks for the diagrams. What is the stroke if the cue goes back in the pendulum fashion and on the forward swing at contact the elbow and upper arm moves down to give a nice long parallel to the table follow through? Is that a pendulum stroke?

I think that's what's called a "J" stroke - it qualifies as a kind of pendulum stroke because the elbow doesn't drop until after contact.

pj
chgo

from dr dave describing the J stroke (imho the best of both worlds.........especially if the eldow drop occurs AFTER CONTACT.......)
i bolded the first part
.......
.........
"J" stroke is a combination of a pendulum and piston stroke, where the grip hand follows the pendulum motion on the back swing and forward swing into the ball, and then the grip moves in a straight line (with elbow drop) after CB contact and during follow through. If you trace out the path of the grip hand, it looks like a "J" turned sideways. If done well, this gives the benefits of the pendulum stroke tip contact point accuracy, and the follow through of a piston-stroke, but some people might have trouble with dropping the elbow at the right time and right amount consistently.

Many pros seem to be close to a "J" stroke, but some pros drop their elbow before CB contact, on some shots more than others. Also, some lift the tip after CB contact, especially with follow shots, and some finish with the tip down (with an almost-pendulum-like stroke finish). Some even swoop their stroke on some shots (usually only shots with english), moving the tip sideways during the stroke (before and after CB contact). Some drop their elbow just a little after CB contact on many shots, and some drop their elbow a lot (mostly after CB contact) on most shots. The one thing that can said for sure is that most pros drop their elbow after CB contact, especially with firmer shots. Some seem to do this purposefully; and for others, it just seems like a natural side-effect of the forward momentum of the cue and arm after CB contact.

 

[Patrick Johnson]

...the J stroke (imho the best of both worlds.........especially if the eldow drop occurs AFTER CONTACT

I think, like me, lots of pendulum strokers let their elbow drop a little with the follow through just to go with the stroke flow and not fight the momentum. I'd rather use a "pure" pendulum stroke if I could get equally comfortable with it - a work in progress, especially on firm shots.

pj
chgo

 

[skipbales]

What the pros do

If you watch the pros play you see every kind of stroke imaginable. You see pendulum, piston, large elbow drop, no elbow drop, swooping seesaw like strokes, short follow through, medium, and long, etc.

Clearly there are a lot of ways to excellence. What Tor Lowry says is "if you want to have a lot of elbow drop you can still reach a high level you will just need to spend a lot more time on the table to be sure you have everything right" (more moving parts).

Teaching is different than playing in that the goal of a teacher should be to guide the student to the simplest way to improve. The student can always choose to follow their own path instead. I think the pendulum stroke is the simplest to teach and to learn. It is also a path that can take the player all the way to the top so there is no downside to teaching it.

There is a difference in starting with a blank slate (new player) and improving a player who has been using a different stroke for years and trying to convert them.

I recently found value in Tor Lowry's "Compact Stroke" or at least my understanding of it. It is Pendulum but not a very long stroke. I found I was adding complexity to my pendulum stroke by taking the stick too far back. The long stroke was not usually necessary and I learned I have a kind of wobble if I go too far back. Not every shot is a break shot.

I had watched his video a lot but what made it sink in was watching the pros with a 13-16" and even longer bridge. Yes the bridge was long but the stroke was much shorter. It was as needed. So sometimes a 16" bridge and a 1" stroke.

Different strokes for different folks, as the saying goes.