How to Curve an Object Ball

[dr_dave]

You can apply the jump dynamics to frozen balls too. Often times when you're faced with a forcible carom ( the draw --> follow gearing kind) but the approach angle is too shallow, a jump/ram stroke can do the trick.

I can't imagine jumping action helping with frozen balls. Do you have a video example to share? Regardless, jumping action isn't required with frozen balls since so many other things are possible. See frozen-ball aiming systems, CB control, and throw.

 

[dr_dave]

That happened to me a while back

Nice. That's a much fancier jump version of Efren's kick-off-the-side-pocket-point shot:

 

[dr_dave]

So I am not crazy after all

I can't verify that.

Bob recently challenged me on the swerve in a thread. I let it go as who am I to challenge him. (Translation- too lazy to video!)

I jump object balls over blocking balls quite often

An OB jump is easy compare to OB swerve. I show both in my video.

I was playing a eye dr. and jumped a 8 ball over a full blocking ball. This time the 8 jumped about a foot off the bed which is way higher then I have ever seen. The Dr. said "When you called the 8 there , I couldn't imagine what you were trying. After you jumped the 8 I am not sure I dont need my eyes checked".

I've never seen an OB jumped that high, but it is certainly possible with a strong-enough stroke and perfect hit (although, I suspect the CB would fly off the table at the speed required). Here's the best OB jump Tom Ross and I got during our VEPS filming:

 

[CocoboloCowboy]

Well Dr. Dave just deliver a free Golden Nugget to anyone who wishes to practice, and learn to do.

Price a little to view, practice, and get incorporated in to your game.

Thanks Dr. Dave.

 

[dr_dave]

Well Dr. Dave just deliver a free Golden Nugget to anyone who wishes to practice, and learn to do.

Price a little to view, practice, and get incorporated in to your game.

As I point out at the end of the video, the OB swerve effect is not really practical in an actual game situation, but it is fun as a proposition/challenge shot.

Thanks Dr. Dave.

You're welcome. I aim to swerve (even with the OB).

 

[straightline]

I can't imagine jumping action helping with frozen balls. Do you have a video example to share? Regardless, jumping action isn't required with frozen balls since so many other things are possible. See frozen-ball aiming systems, CB control, and throw.

Freeze two balls out in the middle of the table and make note of the natural carom. Shoot it from an angle outside the zone where draw will affect the shot. 30 ish degrees give or take. If you bang the carom ball with a very hard stun stroke, the ball will take the impossible line - forward of the frozen tangent. It's not hard to do.

 

[dr_dave]

Freeze two balls out in the middle of the table and make note of the natural carom. Shoot it from an angle outside the zone where draw will affect the shot. 30 ish degrees give or take. If you bang the carom ball with a very hard stun stroke, the ball will take the impossible line - forward of the frozen tangent. It's not hard to do.

Like this?

Or this?

 

[Bob Jewett]

As I point out at the end of the video, the OB swerve effect is not really practical in an actual game situation, but it is fun as a proposition/challenge shot

Particularly because it requires chalking the object ball in order to triple or quadruple the effect. In a few hours of my own tests I got the unchalked OB to hit about 1/4-inch of the far ball frozen on the rail. With dozens of attempts, I couldn't be sure it wasn't just from ball wobble.

My offer of $200 for a method that is usable in a game still stands. Here is the text from my July 2003 column:

In my June 1992 column, I proposed the experiment in curve shown in Diagram 1. Some people claim to be able to make an object ball curve. I don't believe them. Unlike some non-believers, I'm willing to put my money where my mouth is and pay $200 to anyone who can teach me how to make the ball curve. So far, I've had no takers. The balls are as shown, with the object ball in question exactly a ball off the cushion. Can it be made to curve into the far pocket? The shot must be legal to collect on my offer. Since it is impossible to prove an impossibility, I can't say that the shot absolutely can't be done, but until I see it, I'm a skeptic, and will put the "object ball curvers" in the same camp as the Chalk Borers.​

​

Among other forbidden techniques are: chalk the object ball, have the table not be level, have the ball be oval, and have the leaf blower on. Here's the diagram from 2003:

​

 

[Pin]

Great video. I can't quite get my head round the mechanics at first watching (I'd expect the OB to swerve the other way), so I'm off to read Dave's link.

Re Bob's rules: I guess if you spent long enough at it, you could use a lot of chalk on your tip and hope for a natural kick (the chalky spot on the cue ball just so happening to be the part of the ball that contacts the OB). Still not sure it would count as useable in a game, and for $200, your hourly wage might mean you go hungry!

I have a hunch that it could be done with frozen balls (to facilitate the transfer of spin). In fact, ordinary CB draw > OB follow on a frozen carom presumably must curve a little bit (it just looks like a straight line to the naked eye).

Are those 'donuts' just ringbinder reinforcers, or are they something special for pool?

 

[Masayoshi]

Nice. That's a much fancier jump version of Efren's kick-off-the-side-pocket-point shot:

Play it in slow motion, the ball actually hits the rail on the flat comes out about 3-4 ball widths towards the 7, but then curves back to the pocket. Its kind of the same as bending a bank, but it bent a lot more than is normally possible because the ball hit the rail as it was rising.

 

[Pin]

Bingo. Because of the thrown OB direction, the transferred bottom spin to the OB has a masse component. FYI, the physics and math are here if you are interested:

TP A.24 – The effects of follow and draw on throw, and OB swerve​

Now, when you think of the rotation being about the T-axis, the effect makes sense.

When you think of the actual rotation of the cue ball at impact, as I see it, the transferred spin wouldn't make the OB rotate about the T-axis, but a different axis pointing in a slightly different direction.

I think I read in Byrne (years ago) that when you're working out the effects of mixed English and follow/draw, you can think about the effect of each part in isolation. Which could perhaps get you to thinking about just the T-axis, before considering anything else. But it doesn't seem to solve the thing.

Obviously, in some material way I'm wrong - Dr Dave's video proves it. I'm just not sure why I am.

 

[Pin]

Okay, I think I get it now, focusing in on the rotational movement at the contact point.
If you shot it with both English and follow/draw maybe you could shift the axis and get a bigger effect (without chalk). Or maybe I'm still not visualizing it right.

 

[Patrick Johnson]

...a jump/ram stroke

What's a ram stroke?

pj
chgo

 

[dr_dave]

Particularly because it requires chalking the object ball in order to triple or quadruple the effect. In a few hours of my own tests I got the unchalked OB to hit about 1/4-inch of the far ball frozen on the rail. With dozens of attempts, I couldn't be sure it wasn't just from ball wobble.

My offer of $200 for a method that is usable in a game still stands. Here is the text from my July 2003 column:

In my June 1992 column, I proposed the experiment in curve shown in Diagram 1. Some people claim to be able to make an object ball curve. I don't believe them. Unlike some non-believers, I'm willing to put my money where my mouth is and pay $200 to anyone who can teach me how to make the ball curve. So far, I've had no takers. The balls are as shown, with the object ball in question exactly a ball off the cushion. Can it be made to curve into the far pocket? The shot must be legal to collect on my offer. Since it is impossible to prove an impossibility, I can't say that the shot absolutely can't be done, but until I see it, I'm a skeptic, and will put the "object ball curvers" in the same camp as the Chalk Borers.​

​

Among other forbidden techniques are: chalk the object ball, have the table not be level, have the ball be oval, and have the leaf blower on. Here's the diagram from 2003:

View attachment 596286

​

I didn't know about the "fine print" concerning not allowing chalk on the OB. What if a chalk mark just so happened to be there because it was transferred to the OB from the CB on the previous shot? Just pay the man. Oh wait ... the man is me. Even better ... just pay me.

I'm just kidding. I would not have been able to pull off the shots in the video without the ample chalk mark placed on the OB contact point. But as a proposition or challenge shot, I think a chalk mark is fair game. One could even pre-mark the OB with chalk so your "mark" doesn't even know it is there.

 

[dr_dave]

Great video.

Thanks.

I can't quite get my head round the mechanics at first watching (I'd expect the OB to swerve the other way), so I'm off to read Dave's link.

I just added the following near the bottom of the OB swerve resource page:

"Just think about CB swerve from a massé shot. To curve the CB to the left you need to hit down on the left side of the CB. To make the OB swerve to the left, you also need to hit down on the left side of the OB. This is accomplished with topspin on the CB with a cut to the right. The topspin transfers backspin to the OB in the line of centers direction; but because the OB is being thrown to the left, the backspin has a slight masse component. The detailed math and physics (with an illustration) can be found here:

TP A.24 – The effects of follow and draw on throw, and OB swerve"

Re Bob's rules: I guess if you spent long enough at it, you could use a lot of chalk on your tip and hope for a natural kick (the chalky spot on the cue ball just so happening to be the part of the ball that contacts the OB). Still not sure it would count as useable in a game, and for $200, your hourly wage might mean you go hungry!

I like the way you think.

Are those 'donuts' just ringbinder reinforcers, or are they something special for pool?

Yep. They are normal "self-adhesive hole reinforcement labels." The center holes are big enough to where the donuts don't interfere at all while the CB and OB are in contact. The donuts might actually make the Challenge Shot tougher because they probably have more friction than my Simonis cloth, which would cause the OB swerve to happen sooner, making it more difficult to clear the obstacle ball.

 

[dr_dave]

Play it in slow motion, the ball actually hits the rail on the flat comes out about 3-4 ball widths towards the 7, but then curves back to the pocket. Its kind of the same as bending a bank, but it bent a lot more than is normally possible because the ball hit the rail as it was rising.

I noticed that. The ball picks up topspin off the cushion since the cushion nose effectively hits the ball below its equator; so it is very different from the Efren kick shot, where the ball comes into the pocket point with topspin to begin with. The bending action of the shot is similar though.

 

[alphadog]

On newly recovered tables , that appear to be level , there is still a pocket bias as the cloth is last stretched into the pocket causing the slightest roll off.
I insist the shot is possible without doctoring the conditions.

 

[dr_dave]

Okay, I think I get it now, focusing in on the rotational movement at the contact point.
If you shot it with both English and follow/draw maybe you could shift the axis and get a bigger effect (without chalk). Or maybe I'm still not visualizing it right.

Hopefully, my explanation in post 35 helps. It is best to think about the effects of top/bottom and side spin separately. The sidespin component (in combination with the cut angle) can only transfers sidespin to the OB, which cannot cause masse swerve. Only the topspin (and transferred bottom), with throw, can create a masse spin component to create OB swerve.

 

[dr_dave]

On newly recovered tables , that appear to be level , there is still a pocket bias as the cloth is last stretched into the pocket causing the slightest roll off.
I insist the shot is possible without doctoring the conditions.

Any "roll off" (due to table levelness, cloth pocket stretch, leaf blower, etc.) is considered "cheating" with the Challenge Shot. The OB swerve must happen early, so any "roll off" is obvious.

 

[Pin]

Hopefully, my explanation in post 35 helps. It is best to think about the effects of top/bottom and side spin separately. The sidespin component (in combination with the cut angle) can only transfers sidespin to the OB, which cannot cause masse swerve. Only the topspin (and transferred bottom), with throw, can create a masse spin component to create OB swerve.

Thank you, I see that you're right. I find the separation of effects for different directions (axes) of spin very counterintuitive. With combined follow and side, when you think about the direction that a point on the surface of the ball moves, it seems like you should get a swerve effect (which obviously you don't, unless striking down on the ball).

If you played a swerve/masse while cutting the OB, even though you've shot down onto the cue ball, I think that the transferred spin would be the same as if you used a level cue directly on the object ball to apply side and follow/draw. So no swerve effect on the OB, except for the follow/draw against the throw angle per your Colorado State page explanation. Does that sound right to you?

Bob probably knew this when offering the money!