As Big C said, everyone who plays has to pause at the end of their backswing because it is necessary in order for the cue to change directions. But the pause of some people is only a fraction of a second, while the pause for others may be one second or longer.[...]
We've had long discussions about this before.
This is not true.
A pause is something fundamentally different from the fact the cue's velocity goes through zero when it changes direction.
A pause means the forces on the cue are balanced (no net force) and the cue is held in place. Because gravity always acts on the cue, this means the arm muscles are providing an opposing force.
If you examined Allison or Buddy during their backstroke pause, you'd find a balancing force on the cue. It is
not true that their stroke only differs from the many other top players with no backstroke pause by a length of time in the backstroke position. The fundamental difference pausers and non pausers is whether an opposing force exists that holds the cue in place.
A pendulum (child on a swing) and a ball thrown straight up have no pause. The fact the velocity goes through zero is a red herring.
If you wanted a child on a swing to pause at the back of the arc, even for a very short amount of time, you'd have to reach out and hold the swing (even if just for a very short amount of time).
It is important that the transition to forward motion be smooth.
THE NO-PAUSE STROKE:
Slowing down the backstroke and imagining you're letting the cue do it's own pendulum style transition before accelerating forward is a good idea. So in a proper no-bause stroke, the tricep pulls the cue back with a force that smoothly diminishes to zero near the transition. At the transition neither the tricep nor the bicep is contracted and the cue and forearm are doing their thing under the influence of gravity. Then when the cue starts "falling forward," the bicep starts pulling and therefore accelerating the cue forward.
THE PAUSE STROKE:
Here you still do a slow backstroke with the tricep pulling the cue back with a force that diminishes to near zero. Then at the apex of the backstroke the tricep force stays at a level sufficient to hold the cue in place for a desired length of time (could be a couple tenths of a second, could be a few seconds). At the end of the pause the tricep relaxes and the bicep accelerates the cue forward.