What is the rarest pitch in baseball?

What is the rarest pitch in baseball? Definition. A screwball is a breaking ball designed to move in the opposite direction of just about every other breaking pitch. It is one of the rarest pitches thrown in baseball, mostly because of the tax it can put on a pitcher’s arm.

Definition. A screwball is a breaking ball designed to move in the opposite direction of just about every other breaking pitch. It is one of the rarest pitches thrown in baseball, mostly because of the tax it can put on a pitcher’s arm.