Is this jump shot illegal?

[X Breaker]

On that note, the thicker the slate, the easier the jump, for sure.

When I talked to Paul Smith of Diamond, I was told that they use 1.5 inches becuase it helps the ball to stay on the table better. I am no expert, so I am not sure why, but I remember that is what he told me.
He also told me the thicker slate on the 3 cushion table helps the ball to move faster because of lesser vibration.
I have tried jumping on a table with a very thin slate, and it was really easy. I could be wrong but I always thought the really thin slate tables are very easy to jump. Am I missing something?
Richard

 

[Handsumm]

My $.02 -
The shot can be performed with a regulation jump cue, though it's easier with just a shaft, regardless of legality. Pavel Pooler (the second youtube link posted) does it more easily on his table than I've ever seen, but that's because it's a hardwood table with tons of rebound. As to the shot, take a closer look at Larry's angle. When I execute this shot, as he does, I have my shaft at about 98 degrees. That means, it is elevated past vertical. You are technically shooting away from the obstructing ball. Our physics guys would tell you that it compresses the felt in the opposite direction before the rebound would propel it over the ball. So, in effect, a former poster is right in saying that it makes the gap bigger before getting up and over. But, the hit point is either 5:30 or 6:30 on the clock face. This allows the shaft to get out of the way of the quickly rising cue ball. So, in my opinion, when performed properly, it can be, and is legal. I espouse this theory but would love to see highspeed footage regardless, just to know for sure.

-yow!

exactly, thank you for proving my theory of how this shot is executed. The only question that remains is " Is the shot really a good hit?"

In other words, does hitting it at say 5:30 or 6:30 really get the cue stick out of the way enough to avoid the cue ball contacting the shaft in flight?

I doubt it. The cue ball is travelling forward BECAUSE your shaft is angled past 90 degrees and the cue ball is propelled by it.

 

[X Breaker]

If you look at this shot from another angle, you can see that the tip did not really gough the cloth on the table. This shot was clearly hit harder than Larry's XBreaker1mm shot, since the cue ball jumped way higher.

http://www.youtube.com/watch?v=6QOm_Y7nYTM

There was a white dot left on the table after the shot was performed, much like the dots one sees along the break line going from the side rail to the one ball. I believe that dot was formed by the cue ball, not the tip.

I was the one who recorded and posted the 1mm jump video a year ago. When I asked Larry how he did this shot, I remember he told me the key was to find the sweet spot on the cue ball. From what I understand, this spot is very small but it is there. If you hit too close to your body, you will miscues, hit it too far you will trap the cue ball from going up. Once you find that spot, you need to hit the ball with a snap, let the cue gets out of the way of the cue ball so it will jump up.

Of course, a very "hard" tip and a very light cue will help because it allows the cue to rebounce quickly. A tip which holds chalk well can be a benefit as well.

I could be wrong, but I think he was holding the cue at almost 90 degree, so there was a bit of forward vector with the hit he exerted on the cue ball, which makes it physically possible for the cue ball to jump up and move forward. There may be more than one way to make this shot, perhaps using a bigger than 90 degree angle is another way; I just do not recall seeing Larry do that.

I also saw another person made this shot. The way he did it was to hummer the cue down on the cue ball with lots of follow through. The cue tip went all the way down on the cue ball, follow through, and hit the table. His tip never rebounced from the ball.

The shot was made, he also successfully jumped 1mm. Nevertheless, his method would clearly rip the cloth.

 

[arsenius]

OK, why does this not apply to a regular old pool shot ? My tip is round (about the radius of a nickle) and the cueball is round. How the heck do I ever pocket a ball ? No my friend, it is absolutely possible to control this to a sufficient degree.

If the trajectory changes in mid-flight, the cue ball must have been hit a second time. While high-speed video would be required to actually see any second hit, analysing the trajectory of the cueball might be possible with lesser video.

Dave

On a regular stroke, your shaft is all going in one direction, directed by your bridge and stroke arm. To make the ball go forward with your shaft on this shot, you would have to change directions, from your quick forward motion guided by two points, to hit the cue ball with the shaft. Much more difficult. Not to mention that usually when you shoot a cue ball it is sitting quite still on a table...

 

[X Breaker]

This is the video whereas Larry Nevel jumped the balls when they were almost frozen, and he jumped too far!

http://www.youtube.com/watch?v=zJyin1W1bUM

I labelled it 1mm just so that it can be visualized easier, I believe this shot was closer than 1mm.

It shows a better angle than the other X Breaker 1mm jump of how close the balls were.

Larry was very vertical with his cue, and his cue ball jumped up without any double hit. If this shot was done on a Gold Crown, the ball may hit the rubber lid around the pocket and bounce back on the table.

Larry is such an amazing player!

Richard

 

[TheSniper]

It's a pain to hit the pause just right, but there is a frame that has an overlapped image of the cue ball and cue just before being struck with a second image of the cue ball rising vertically placing the origin of the trajectory maybe a 1/2" or more away from the original spot.

I wish I could freeze it and post it here because it definitely convinced me that it was a double hit.

Still, a very very cool shot though!

I got the pause just about right, looks like the cue ball hits the shaft.

See if this helps the debate.

P.S. what is with this guys pool table, the side pockets stick out like an inch or more out from the rail, it looks as though you could slow roll a ball up the rail and pot it in the side.

 

[SphinxnihpS]

Completely legal, with a legal length cue, and no sort of double hit, and not even all that hard to do.

I for one though, think that the game of billiards is going the same way as golf. It's getting to be so that everyone has at least two or three cues they use in different situations. The standards for cues should be something like 17oz-22oz and 55"-61". These shots should be reserved for the realm highly skilled players who can accomplish them with standard equipment. The average decent player should not be able to get out his 40" 6oz cue every time he hooks himself. Besides, every jumpshot is destructive to the cloth, and not because the cue even touches it, but because the ball is being driven into the slate with such force and a super high rate of spin that the threads of the cloth get crushed, and even though it is not evident immediately, the spot on the cloth will disintegrate.

 

[Bob Jewett]

I got the pause just about right, looks like the cue ball hits the shaft.

See if this helps the debate....

It looks like his shaft is angled in the usual direction for the jump shot. Larry Nevel is said to angle his shaft in the other direction (I believe). Also, a table like the one shown probably has a plywood bed and burlap cloth. So.... I'd say we need more data.

 

[8ballEinstein]

Call me stubborn but I still have doubts that the cue ball hit the shaft. It was good work by theSniper to capture the image. I tried numerous times to no avail.

What we see is a white oval (the rising cue ball) and two distinct locations of the cue stick, one at the point of initial contact and then the sidestep away from the rebounding cue ball.

I examined the still shot and this is what I think is going on - the shooter was shooting the cue ball at 5:30 english. So what looks like cue ball contact with the shaft is actually the cue ball partially in front of the shaft. I gathered this from where the tip of the cue stick is at in relation to the center of the side pocket. There is one problem with my argument, the cue ball appears to be going backward. I can't explain this one. There is something else going on. Bob Jewett is right, more data is needed.

His table does have large pockets but I doubt it has a plywood bed. After all the masse shots he did for the 3 videos, I think his table would be useless by now.

 

[Da Poet]

The thing is that even if it is possible to occasionally hit this shot legally, it is also very possible that the cue ball can hit the shaft on the way up so quickly that it is impossible to referee. It might be more practical to somehow not allow it for that reason.

A high speed camera analysis should still be done to confirm this for everyone.


By the way, nice job Sniper!!!!!

 

[Solartje]

larry

looks like no double hit... but it all depends. is a cb frozen to a rail a double hit?

richard do you have the original footage?

 

[X Breaker]

Sol,

Yes, here are most of the files of jump and break shots made with the X Breaker. I have uploaded them onto YouTube.

http://www.youtube.com/profile_videos?user=XtremeBilliard

Thank you.

Richard

 

[Solartje]

richard, on you tube the fps is really slow :s

was hoping u could email me the original video of the camera, witch would have more frames / sec i hope so i can make a better slowmo of the movie so everyone can see what exactly is happening.

so if u got a better quality video then on youtube(who reduces them) pm me, and ill be glad to make some slowmo's for the viewers.

ps charly braints break in slowmo is AMAZING to watch. i learn from it every day. thank god we have technologie

 

[tigerallenyim]

The thing is that even if it is possible to occasionally hit this shot legally, it is also very possible that the cue ball can hit the shaft on the way up so quickly that it is impossible to referee. It might be more practical to somehow not allow it for that reason.

A high speed camera analysis should still be done to confirm this for everyone.


By the way, nice job Sniper!!!!!

yeah.... i have to agree with u.... with too many different explanations and possibilities, it does not leave a concrete answer if the shot was legal. Great shot i must sat.

belmicah: yeah, i don't know much about physics (only took 101), not even about jumping, or even a pro player, but i do visualize things well. And I have to tell ya, what u described is the only way i can imagine that kind of shot being executed, and brings the question of whether the cue ball makes contact with the shaft.

 

[Handsumm]

Thank you for agreeing on this issue. In fact, the video freeze proves this, but people are still weary to believe it. I mean, look at the cue ball...not only does it go BACKWARDS first, but you can see it contacting the shaft (not "in front of it")

Ahhhh well, can't win 'em all.

 

[ericyow]

Bob, the guy's name is Pavel, he's Czech. The table in the video with the giant pockets is in fact a plywood bed with burlap cloth.
-yow!

 

[Handsumm]

Eric, your trick shots are BADASS!! But, can you do this shot? If so, how? Input from a trick shot artist would be beneficial here.

 

[juggler314]

Mathematically possible

Ok...

with a 1mm gap you can use geometry to show that the common tangent line will give a 75 degree angle at most for the jump. (using some geometry you can show there is a right triangle with sides of 28.575, 29.575 and 7.625 mm, then use your favorite trig function to find the angle).

Using 75 degrees and estimating the distance (to me it looks like the cue ball is lined up with it's right edge right at about the diamond, and that it lands right about with it's left edge hitting the phantom diamond in the pocket). As 1 diamond - the cue ball width (2.25 inches) we get a jump distance of 11.25/9.75/8.25 inches (for 9/8/7 foot tables respectively).

Two steps - calculate first initial minimum velocity for cue ball using sqrt(<travel distance><gravity = 9.8m/s squared>/(-2*sin(75)cos(75))) (PS don't forget to tranform the inches into meters so you get units right!)

then using Vo calculate the height needed (remembering that these are minimums for perfectly almost hitting the object ball during the jump) using:

(Vo)^2*(sin^2(75))/2*<gravity=9.8m/s squared>

this gives minimum heights of the parabola of 9.46/8.20/6.93 inches (for 9/8/7 foot tables respectively).

On the video the apparent jump height is more than the jump length implying that the angle the cue ball leaves the table is actually greater than 75 degrees, but probably not by much - may 80 degrees (don't feel like doing more excel work).

Obviously this is very rough, exact measurements are hard from video, and I didn't take the time to screen cap and measure, besides the POV is not square on so perspective might skew those measurements anyway.

I'm not saying there isn't a double hit, just that the math works out that it is theoretically possible to jump from 1mm apart!

Definitely need high speed video, the guy that writes that column every month in one of the billiard mags has shown that even some masses that everyone would call routinely legal result in a double hit. I think that for reffing wise if you can't determine a double hit without HSV, it's good...unless it can be shown that it is impossible for the cue to move away from the ball fast enough...

-chris

 

[juggler314]

forgot to add

those parabola heights are for the left edge point on the cue, so add 1.125" for the top of the cue...

 

[Handsumm]

Ok...

I'm not saying there isn't a double hit, just that the math works out that it is theoretically possible to jump from 1mm apart!

Definitely need high speed video, the guy that writes that column every month in one of the billiard mags has shown that even some masses that everyone would call routinely legal result in a double hit. I think that for reffing wise if you can't determine a double hit without HSV, it's good...unless it can be shown that it is impossible for the cue to move away from the ball fast enough...

-chris

Nice proof, but....
you have shown that it is possible for a ball to get over an impeding ball that is 1mm away yes, but it is IMPOSSIBLE for the cue ball to be struck only once, to move BACKWARDS (as seen in the screenshot), and then travel FORWARD without hitting the shaft or other part of the cue stick.