Live ball (baseball)

A ball may not become live until the pitcher is on the rubber ready to pitch and the batter, catcher, and umpire are ready--much like in this photo, taken during the August 27, 2005 Cubs-Marlins game.

In baseball, when the ball is alive (or in play), the game can proceed. The pitcher may pitch the ball, the batter may attempt to hit such a pitch, baserunners may attempt to advance at their own risk, and the defense may attempt to put the batter or baserunners out.