1mm Jumps are NOT legal, I'm convinced

ericyow

ericyow

WPA Masse World Champion
Silver Member
There was a thread (I don't feel like digging up) where many of us were discussing the legality of the 1mm jump. I promised I'd tape it and slow it down, and I finally did. It's not high speed, but you'll see it all you need. As I've explained before, I elevate to about 95 degrees or so (past vertical, for the numerically challenged)(as you can see in the clip) and shoot at about 6:30. After playing around with it for a few minutes, I also made the jump several times at 85 degrees, but the effect is the same. The ball jumps straight up and comes off the shaft to go forward. I was at one time convinced the shot was legal. I'm convinced now that it is NOT legal, even though I make it with a full jump cue. I invite the dogmatic to prove otherwise with a comparable video, as I would love to find out I'm wrong on this.

http://www.ericyow.com/videos/1mm.wmv (right click and save this one)

Streaming - http://www.youtube.com/watch?v=XK9_kZToGLs

-yow!
 
Last edited:
Too close to the OB.
The angle at which the CB goes airborne is not enough to get it past the OB.

I guess we could find physical proofs that the CB would have to get to 1m or even higher to get past the OB.
 
It's clear in the video. The cb does in fact contact the shaft. Regardless, it's one hell of a shot.
 
Video ...

Eric ... Thanks for the video. But, I would like to see Larry Nevel's 1mm jump shot video broken down to slow-mo that is on the X-breaker website. If, in fact, his showed the same thing as yours, then I would be 100% convinced.
 
Snapshot9 said:
Eric ... Thanks for the video. But, I would like to see Larry Nevel's 1mm jump shot video broken down to slow-mo that is on the X-breaker website. If, in fact, his showed the same thing as yours, then I would be 100% convinced.
Click to expand...
Yeah, Im with you snapshot. There may be differences in technique.

However, using the shaft only like Larry did it would be illegal. A regulation jump cue would be needed to make it legal provided the hit is ok.

Regardless, great video Eric!
 
Snapshot9 said:
Eric ... Thanks for the video. But, I would like to see Larry Nevel's 1mm jump shot video broken down to slow-mo that is on the X-breaker website. If, in fact, his showed the same thing as yours, then I would be 100% convinced.
Click to expand...

In order to get over the ob the cb would have to be moving forward as well as upward. At 1mm there is not room to be going forward so it has to get the forward momentum from hitting the cue.
 
That's what I'm screamin. I'd like to see Larry's broken down too, though I believe his will show the same result. Thanks for watching.
-yow!
 
Sensation: your post about deriving the height of the jump made me curious! This is actually a fairly tricky problem - but I decided to tackle it. With a few simplifications, I found that this jump could THEORETICALLY be made with a launch angle of 80 degrees from horizontal. This means that the height of the jump needs to be at least 1.35 X the distance of the jump.

So according to theoretical physics, if the cue ball were positioned 1mm from an object ball, and were launched at an 80deg angle, you could jump the ball 24 inches forward with a max height of about 32 inches.

OF COURSE, this says nothing about whether this is actually possible in real life, given the physics of the tip, cloth, and slate reactions.

Jon

ps. at 2mm, launch angle is 75deg, max h = jump distance
 
Icon of Sin said:
Yeah, Im with you snapshot. There may be differences in technique.

However, using the shaft only like Larry did it would be illegal. A regulation jump cue would be needed to make it legal provided the hit is ok.

Regardless, great video Eric!
Click to expand...

I agree about the shaft only jump being illegal, however, not every game or match or tournament will abide by a 40 inch minimum cue length.

One player told me that shaft only jump shots were allowed at a recent Viking Tour tournament.

Flex
 
When we were talking about it last thread, I remarked that Ppooler's shot WAS indeed a foul (you could see that it hit his shaft). But, I think that Larry Nevel might have used the rail to redirect the cueball off the cushion and into the object ball that was a little out from the corner pocket. I may be wrong.

Anyways, the way you described the shot, is exactly as I suspected it HAD to be performed. Impossibile if not using the rail.
 
jondrums said:
Sensation: your post about deriving the height of the jump made me curious! This is actually a fairly tricky problem - but I decided to tackle it. With a few simplifications, I found that this jump could THEORETICALLY be made with a launch angle of 80 degrees from horizontal. This means that the height of the jump needs to be at least 1.35 X the distance of the jump.

So according to theoretical physics, if the cue ball were positioned 1mm from an object ball, and were launched at an 80deg angle, you could jump the ball 24 inches forward with a max height of about 32 inches.

OF COURSE, this says nothing about whether this is actually possible in real life, given the physics of the tip, cloth, and slate reactions.

Jon

ps. at 2mm, launch angle is 75deg, max h = jump distance
Click to expand...

I ain't no physician and it shows!

Now what would be the minimum height for the jump shot to clear the OB? I guess it's pretty high. 20" ??
 
Sensation said:
I ain't no physician and it shows!

Now what would be the minimum height for the jump shot to clear the OB? I guess it's pretty high. 20" ??
Click to expand...

Just an FYI:

Physician - Someone who practices medicine.
Physicist - A scientist whose field is physics.
 
I have a scanner - and I'm not afraid to use it!

Sensation: I bet I didn't word that as good as I could have!

I said:
"if the cue ball were positioned 1mm from an object ball, and were launched at an 80deg angle, you could jump the ball 24 inches forward with a max height of about 32 inches."

I meant that you could clear an OB 1mm away from the cue ball with a jump that landed 24" away. This shot would only go 32" high.

You could also completely clear the OB (which is 1mm away) if you could fire the cue ball 6" inches in the air, and land 4.5" away from the original position. (see attached image)

Jon
 

Attachments

  • 1mm_jump.jpg
    1mm_jump.jpg
    28.7 KB · Views: 400
Ok from my undergrad physics I threw together a model with IDL .

1mm, 85 degree jump with a velocity to get almost 7 ball heights (~16 in) lands about half a ball past the object ball. In most of the shots the jump shots land about 3-4 balls away. But to do that at 85 degrees would need about 2 feet of height which is much more than what I've seen.

In another video I saw it looked like the cue ball comes away from the obj ball before taking off so that small increase in separation may be enough to allow for a decrease in angle and less height.
 

Attachments

  • jump.jpg
    jump.jpg
    69.2 KB · Views: 392
skyman said:
Ok from my undergrad physics I threw together a model with IDL .

1mm, 85 degree jump with a velocity to get almost 7 ball heights (~16 in) lands about half a ball past the object ball. In most of the shots the jump shots land about 3-4 balls away. But to do that at 85 degrees would need about 2 feet of height which is much more than what I've seen.

In another video I saw it looked like the cue ball comes away from the obj ball before taking off so that small increase in separation may be enough to allow for a decrease in angle and less height.
Click to expand...
Yeah, because it has extreme back spin and rolls off the shaft like Eric showed in his video. It is impossible to travel backwards, and then to travel forward, avoiding the impeding ball, without another force.

Here we go again...... "physicists" with no common sense:rolleyes: :rolleyes: :rolleyes:
 
How about wrapping a piece of carbon paper around the shaft and then trying this. If someone can clear the jump without putting a mark on the cueball, I'll be a believer. until then, nope.
-Rob
 
  • Like
Reactions: sde
You must log in or register to reply here.
Back
Top