Following up on Hu.ShootingArts said:What I normally consider pocket speed is different however. I believe defining it as the speed that gives the best chance of falling is the best definition. It is very hard to jaw a ball shot at pocket speed.
Hu
Pocket speed is relative to the angle you are shooting at. If you are at an angle that you will hit a pocket facing - pocket speed will allow you to hit one or both facings and then drop, rather than hit two (or more) facings and jaw or even eject. If you hit one facing and jaw the ball, well you have hit the ball just under pocket speed. An example of this comes up when you are shooting at an extreme angle and hit the rail just before the pocket. If you shoot at pocket speed, you will still pocket the ball. Also, pocket speed can be affected by (not an exhaustive list):
the size of the pocket, the facing angles, the type of shims used, the speed of the cloth, and the pocket shelf.
For a straight in shot, pocket speed results in the ball not hitting the back of the pocket. Another way to think of it is that the ball has just enough speed to fall into the hole. For straight in shots, pocket speed is more relevant for cue ball position than pocketing the object ball.
-td