Illegal Pitch (Fast-Pitch)

USA Softball's fast-pitch rules (Rule 6A) cover the setup and the delivery. Before the pitch, the pitcher stands with both feet on the ground within the 24-inch length of the pitcher's plate. Her pivot foot touching it, and takes or appears to take a signal with her hands apart. She then brings her hands together for at least one second and no more than 10 seconds. The pitch starts when the hands separate.

Common illegal acts during the delivery include stopping or reversing the forward motion after the hands separate. This makes two full revolutions of the arm, and releasing the ball other than underhand with the hand below the hip. Pushing off from anywhere other than the pitcher's plate is illegal. That includes the crow hop, where the pivot foot replants and pushes off a second time. Lifting the pivot foot off the plate and putting it back down is also illegal. For women and girls, the stride must go toward the batter and land within the 24-inch length of the plate. Dragging the pivot foot, or having both feet in the air on the push (a leap), is legal for women and Junior Olympic girls.

The penalty depends on the division. In Junior Olympic fast pitch, the standard penalty is a ball on the batter; runners are not automatically moved up. In adult fast pitch, the penalty is a ball on the batter and one base for each runner. In both, if the batter hits the pitch, reaches first and every runner advances at least one base. The illegal pitch is canceled and the play stands. Otherwise the offensive coach picks the result of the play or the penalty. A Junior Olympic batter hit by an illegal pitch she did not swing at is awarded first base. High school and college rulebooks set their own pitching rules and penalties.