[MrUmpire]

Originally Posted by BigUmp56

From the J/R:

Balks

It is a balk if a pitcher:


9. Does not step to a base in throwing (or feinting a throw) to such base.


Tim.

From the OP:

9. after a feint or throw to a base from the rubber, fails to disengage
the rubber before reengaging and pitching;