Not to be argumentative, but the part about "However, with an elevated cue, there is some sliding (due to the masse spin) before complete roll occurs, " just doesn't make sense to me.
The CB can have sidespin (left or right), top/bottom spin, and/or masse spin (AKA "corkscrew spin," "barrel roll" or plane/boat "roll"). With cue elevation and an off-center hit (left or right), the CB develops both sidespin and masse spin. Masse spin is what causes swerve (curving of the CB's path). During swerve, there is sliding motion between the CB and cloth. This sliding creates a friction force which is responsible for the curving of the CB. Once the sliding (and swerve) stops, the CB begins to roll and it heads in a straight line (with or without sidespin). This effect is exaggerated with a fast-speed masse shot, where the masse spin persists over a large distance and long time (especially on slick cloth). However, the masse spin and swerve effects occur with any shot where the cue is not perfectly level (i.e., with practically every pool shot). At lower cue elevations and slower speeds, the effect is small and happens very quickly, but the effect is still there.
Have you ever seen the
Coriolis aiming method for masse shots? If not, check it out. It can actually be used to predict the amount of swerve for any shot, even typical pool shots with only a small amount of cue elevation.
If the tip contacts the ball above the axis that is parallel to the bed of the table, the ball has to start off rolling.
... only if the tip is at the correct height. For more info, illustrations, and demonstration, see:
If the tip contacts the ball right on the axis that is parallel to the bed of the table, the ball has to start off sliding.
Yes. In fact, if the tip contact the CB at any height other than the roll height, the CB will slide at first; although, roll will eventually develop ... sometimes quickly. For more info and illustrations, see:
And if the tip contacts the ball below the axis that is parallel to the bed of the table, the ball has to start off back spinning.
Correct, for the same reason.
AI don't see any way that a ball that is hit above the level centerline can possibly slide, even with an elevated cue.
Sliding can be due to stun or bottom-spin drag, but it can also be due to masse spin. Again, masse spin occurs anytime the cue is not perfectly level. At a pool table, the cue is practically never perfectly level because it must be elevated to clear the rails, even with follow shots.
if you are indeed hitting your shots above the level centerline, you can keep the cue almost "dead" level.
It can certainly be more level than with a draw shot, but it still can't be "dead level." In fact, one reason accuracy can be better with an above-center hit, is that there is less swerve. For more info, see:
And when I tested my theory of above-center hits, I used three different shafts. One was graphite, one was a 13mm standard maple, and one was a Predator 314. Interestingly enough (to me, anyway), there was no noticeable difference in any of them. Squirt and swerve were essentially non-factors. When I dropped down to the level centerline, however, it was a different matter.
If you use the exact same cue elevation, shot speed, and tip contact point for all shots, the difference might be small (for slow-speed hits, with the cue as level as possible), but there should be a difference ... there certainly is when I do careful tests. As you know, a small difference can make a big difference at a pool table (especially with long shots and tight pockets).
When you drop down to centerline, the cue elevation and swerve increase. The squirt will be different for each cue, but for identical hits, the swerve should be the same for each. Again, the net result should be different for each cue.
Regards,
Dave
...the suggestions "play with a center ball and/or level cue" is a recipe for a LOT of missed shots.
