Sidearm 侧肩投法
In baseball, sidearm is a motion for throwing a ball along a low, approximately horizontal axis rather than a high, mostly vertical axis (overhand).
Sidearm is a common way of throwing the ball in the infield, because many throws must be made hurriedly from the glove after fielding ground balls. An infielder’s quickest throw to the bases is often from just above ground level, necessitating a horizontal release of the ball.