pitching motion; windup
Baseball term for the full set of movements a pitcher makes when delivering a pitch.
His pitching motion is very smooth.
He was called for a balk in the middle of his windup.
投球 refers to a pitch or the act of pitching, while 投球動作 specifically refers to the physical motion or mechanics of the pitching delivery.
Compound of 投球 (pitching) and 動作 (motion, movement).