How does it change the entry angle by moving up or back on the approach?
I'm trying to remember what my coaches said back then. Keep in mind, this was 25 years ago.
Also, I should caveat this by saying that I am not talking about a 6" or full step back or forward on the approach. I'm talking maybe 1" or 2" at the most.
Now. As for how it changes the entry angle. With that small of a move, the ball, which should be on its same line to the pocket, should start its turn to face the pocket earlier or later (depending on if you moved up or back). This is slightly different from the ball checking up earlier due to carrydown, which you would have to adjust left or right to find the oil for your ball to push down to the breakpoint you are looking for. But the slight move up or back is sometimes all that is needed to change that entry angle.
I must be one the few that moving up and back works for the majority of the time. If I leave a ten I can move up 2 inches and go right back to carrying 9 times out of 10. If I move up too much I'll leave a 7.
That's exactly how it is for me as well, but slightly opposite. If I leave a 7, I'll move up, and can carry it. If I leave a 10, I'll move back and can carry it. This is all assuming same line, same breakpoint. Once the ball checks up before the breakpoint, then I'd have to move left.
BL.