Bob Jewett said:
I think I can answer this one. Essentially all shots are hit with some elevation. A level stick would require the center of the bumper to be at the same height as the center of the tip at tip-to-ball contact. That doesn't happen except on contrived shots. It is possible to contrive a shot with negative elevation, but not with a normal grip.
To the best of my knowledge, all break shots are hit with elevation of at least 2-3 degrees. Two degrees of elevation means that the center of the bumper is two inches above the center of the tip at the time of contact.
Bob, with great respect, it is not correct that to achieve a level cue, one must shoot a "contrived shot."
Let me hasten to add that most shots ARE executed with at least some downward slant...but that was not the point of contention between Patrick and me. He stated that a shot cannot be executed with a level cue...but it can...and without being contrived.
If my Olhausen Accu-Fast cushions can be considered typical in terms of the elevation of the top surface above the bed of the table, then here is the math.
The height above the surface is exactly 1.25 inches. Of course, the cb diameter is 2.25 inches. Therefore, one full inch of the cb protrudes above the cushion.
The stripe of an Aramith Super Pro ball is often said to reference the highest/lowest point on a pool ball where tip contact can be made without serious risk of a miscue.
Placing the 9 ball so that the stripe is as close to parallel to the surface an the naked eye can determine, 5/16 of an inch of the stripe protrudes above the cushion.
Since the cusion is the only impediment to a level stroke, it is clear that an above-center tip contact point well within the boundary of the stripe can be readily made.
In fact, slightly more than a tip above center...which I contend is not a contrived impact point any more than the same relationship below center would be...will result in a virtually level cue.
In fact, to achieve cue tip contact at the upper limit of the stripe requires a slightly elevated cue due to the fact that the lower half of the tip will contact the upper portion of the stripe.
Again, for clarity, the debate was NOT what is "normal" or "recommended" but rather what was possible. The issue of whether "possible" might also be "contrived" did not enter into the discussion, but I will accept it as a given in any event.
Therefore, I would appreciate your comments on whether a level cue can, in fact, be achieved with a "non-contrived" above-center tip impact point as described above...Again, not "recommened" but "possible without contrivance."
THANKS!
Jim
PS:
A level stick would require the center of the bumper to be at the same height as the center of the tip at tip-to-ball contact.
Bob, I beg to differ with you on that. In fact, the bottom of the arc of the tip and the arc of the bumper lie on the same plane. But due to the taper of the butt vs. the shaft, the center of the tip and the center of the bumper do not lie on the same plane.
On my cue, the center of the bumper is about 10/16 above the table while the center of the tip is about 3/16. Therefore, for the center of the butt and tip to be at the same elevation, the cue would have to be tilted upward.
What am I missing??
THANKS!