icebreaker tips

[Patrick Johnson]

RRfireblade:
The issue with trajectory is that as you elevate to greater extremes the cue has more difficulty getting out of the way of the ball. In order for it to do so , it has to 'roll' or deflect down the back of the CB with adds an amount of back spin and effectively steepens the forward arc. It needs impact from the shaft to regain foward momentem to get over the OB.

Me:
This isn't true. If backspin makes the CB go up at a steeper angle, all you have to do is aim it at a lower angle. Nothing prevents you from giving it the angle it needs to clear the OB without shaft interference.

Of course, it still may be impossible to hit the CB so steeply and get the shaft out of the way of the CB as it jumps up, but that's a different question.

RRfireblade:
What ? Do you actually read what you post ?

You said backspin makes the CB jump at a steeper angle, and shaft interference is needed to compensate for that. I said shaft interference is not needed; all you have to do is adjust the original angle of your stick to compensate for the "steepening" effect of backspin.

Did you actually read what I posted? If so, what part do you disagree with?

pj
chgo

 

[RBC]

Patrick,

Great posts!

I have to admit that I am surprised that you can get there with only a foot or so in height! I did the numbers a while back and thought it was a little higher.

However, if you look at these shots, I don't think they are getting quite to 12", and even if they are close to that, the cue ball is traveling a bit past the interfering ball when it should be just clearing it.

Have you done the same drawing but adding the cue shaft? I wonder if the path of the cue ball could be traced along with the location of the cue shaft at the time of the contact. This would at least show how far the cue shaft would have to move in order to get out of the way!

Your contributions to subjects like this are always good! I will give you some rep as soon as I figure out how! lol!

Royce Bunnell
www.obcues.com

 

[sde]

The graph shows this: with air resistance the amount of time going up is less than the amount of time coming back down, but without air resistance the two times are the same. Again, this shows that the difference is from air resistance, not gravity, so we can assume that it would have negligible effect on the amount of forward movement for the CB.

To pick a nit: I think the differences in time and distance traveled during rise and drop are both results of air resistance, and neither of them affects the other (they're just different ways of measuring the same thing).

pj
chgo

I was just guessing that there may be difference in time intervals not because of air resistance but because of force of the cue to raise the CB vs the force of gravity to returned it to the table.

Would those two different forces, disregarding air resistance, result in equal or different time intervals.

It seems to me that IF there was a difference in time it would result in a difference in the amount of forward travel given the same forward speed.

Please excuse my improper terms.

Steve

 

[Patrick Johnson]

Royce:
I have to admit that I am surprised that you can get there with only a foot or so in height! I did the numbers a while back and thought it was a little higher.

I just eyeballed the clearances with a highly magnified CAD drawing done to scale, so my measurement is approximate. But it's close enough for government work.

However, if you look at these shots, I don't think they are getting quite to 12", and even if they are close to that, the cue ball is traveling a bit past the interfering ball when it should be just clearing it.

Well, it could be that the shaft is helping it along. I don't know whether it's possible to make these jumps without shaft interference; I just know that the angle is possible without shaft interference.

Have you done the same drawing but adding the cue shaft? I wonder if the path of the cue ball could be traced along with the location of the cue shaft at the time of the contact. This would at least show how far the cue shaft would have to move in order to get out of the way!

The video on Dr. Dave's website (linked above) shows that pretty clearly.

Your contributions to subjects like this are always good! I will give you some rep as soon as I figure out how! lol!

Thanks a lot. Don't worry about the rep. I don't pay much attention to it anyway.

pj
chgo

 

[NINEBALLART]

I guess I can agree that it could be possible to do this shot , but does the shaft get in the way and the cue ball bounce off it ???? How can a ref with the naked eye see and detect that ??? So I'm just saying a ref should not be able to call this a legal shot because he doesn't know for sure.....Would you agree with that ?????

 

[macguy]

I guess I can agree that it could be possible to do this shot , but does the shaft get in the way and the cue ball bounce off it ???? How can a ref with the naked eye see and detect that ??? So I'm just saying a ref should not be able to call this a legal shot because he doesn't know for sure.....Would you agree with that ?????

I guy I used to know years agowho had refed a zillion matches Cue Ball Kelly always said, it is the responsibility of the player to shoot a shot so it can be called or play another shot. If you hit a split hit a 100 MPH and he can't call it, he would just call it bad. I think his thinking made sense. You can't be putting the ref in a position on shots that can't be called. Much less doing it on purpose, like my example with the split hit.

 

[RBC]

Macguy

I used to know a few refs who would make calls the same way. If they felt the shooter was trying to make it too hard to call, then they would call it bad. I also have known many who would call in favor of the shooter. In other words, if they couldn't tell it was a foul, then it was good.

I think now with the training we have for refs today, neither of these two modes of thought are correct. Today, the refs know to watch where the balls go to determine which one was hit first. This is not only the best way, it is also the easiest. I always think it's crazy to actually try to see which ball was hit first. If its close the odds for making a mistake are huge. But, once you have looked at how the shot sits, most refs could call the correct hit from across the room!

I agree that these jump shots are most likely a double hit. I just don't see the ball coming up the short distance they do and still go forward without being hit by the shaft. Now, as Patrick has shown, if the ball comes up a foot or so and just barely clears the interfering ball, then it might have been a good hit. I have just never seen one. I have seen several pro's shoot this shot, including Larry Nevel, and I thought they were all fouls. The cue ball just didn't come up even a foot, and they cleared the interfering ball by at least a couple of inches.

This is an interesting topic!

Royce Bunnell
www.obcues.com

 

[Patrick Johnson]

Macguy

I used to know a few refs who would make calls the same way. If they felt the shooter was trying to make it too hard to call, then they would call it bad. I also have known many who would call in favor of the shooter. In other words, if they couldn't tell it was a foul, then it was good.

I think now with the training we have for refs today, neither of these two modes of thought are correct. Today, the refs know to watch where the balls go to determine which one was hit first. This is not only the best way, it is also the easiest. I always think it's crazy to actually try to see which ball was hit first. If its close the odds for making a mistake are huge. But, once you have looked at how the shot sits, most refs could call the correct hit from across the room!

I agree that these jump shots are most likely a double hit. I just don't see the ball coming up the short distance they do and still go forward without being hit by the shaft. Now, as Patrick has shown, if the ball comes up a foot or so and just barely clears the interfering ball, then it might have been a good hit. I have just never seen one. I have seen several pro's shoot this shot, including Larry Nevel, and I thought they were all fouls. The cue ball just didn't come up even a foot, and they cleared the interfering ball by at least a couple of inches.

This is an interesting topic!

Royce Bunnell
www.obcues.com

I agree we know enough now that a well trained referee shouldn't have to guess about too many shots, but how many referees are really well trained?

The WPA World Standardized Rules say split hits go to the shooter.

http://www.wpa-pool.com/download/WPA_Regulations.pdf

Regulations

26. Split Hits
If the cue ball strikes a legal object ball and a non-legal object ball at approximately the same instant, and it cannot be determined which ball was hit first, it will be assumed that the legal target was struck first.

I think that until it's shown pretty conclusively that this jump can't possibly be made without a shaft foul, the call has to go in favor of the shooter like split hits.

pj
chgo