4p BALL FALLING INTO A POCKET WITHOUT BEING HIT.
(a) If a ball falls into a pocket without being hit by another ball, having been motionless for five seconds or longer, and being no part of any stroke in progress, it is replaced and play continues.
(b) If a ball falls into a pocket by itself during a shot, so that it would have been hit by another ball were it still there, then it is replaced and all balls that moved during the shot are returned to their former positions prior to the next shot.
The player may then play the same shot OR chooses a different shot.
(c) If a ball balances momentarily on the edge of a pocket and then falls it counts as in the pocket and will not be replaced.
