Rulebook 8.05 Comment

[SanDiegoSteve]

Originally Posted by canadaump6

Any takers?

Alright, I'll give it a shot. If a runner is going, it's too late to tell the pitcher, who's leg is already raised, to spin and throw without balking. It would require some hesitation on the pitcher's part, which would result in a balk. The move must be in a continuous motion, with no hesitation or stopping of momentum to be legal. In order to execute the spin move, it needs to be a planned out move by the pitcher, not something he thinks about at the last second.

The move is usually just used to drive the runner back to 2nd base so he will shorten his lead on the next pitch, knowing that the pitcher may try to pick him off, and therefore not getting as good a jump on a base hit. That little edge can mean the difference between a runner scoring or being thrown out at the plate.