In baseball

Baseball

Baseball is a bat-and-ball sport played between two teams of nine players each. The aim is to score runs by hitting a thrown ball with a bat and touching a series of four bases arranged at the corners of a ninety-foot diamond...

, the time of pitch is that instant when the pitcher

Pitcher

In baseball, the pitcher is the player who throwsthe baseball from the pitcher's mound toward the catcher to begin each play, with the goal of retiring a batter, who attempts to either make contact with the pitched ball or draw a walk. In the numbering system used to record defensive plays, the...

 has begun his pitching motion and, by the rules, has committed himself to throwing the pitch. This instant thus occurs before the pitcher actually releases the ball

Ball

A ball is a round, usually spherical but sometimes ovoid, object with various uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for simpler activities, such as catch, marbles and juggling...

. Once a pitcher commits himself to throwing a pitch, it is illegal for him to return to his set

Pitching position

In baseball, there are two legal pitching positions: the windup, and the set. Each type of pitching position has its strengths and weaknesses. Compared to the set, the windup takes a relatively slower execution, so therefore is better suited for situations in which there are no baserunners, or when...

. If that happens, he is charged with a balk

Balk

In baseball, a pitcher can commit a number of illegal motions or actions that constitute a balk. In games played under the Official Baseball Rules, a balk results in a dead ball or delayed dead ball. In certain other circumstances, a balk may be wholly or partially disregarded...

, and any baserunners are allowed to advance a base.

A baserunner's time-of-pitch base is the base which he has last legally reached at the time of pitch.