In baseball rules, a catch occurs when a fielder gains secure possession of a batted ball in flight, and maintains possession until he voluntarily or negligently releases the ball. When a catch occrus, the batter is out, and runners, once they properly tag up (retouch their time-of-pitch base), may attempt to advance at risk of being tagged out.Unlike in American football and other sports, neither secure possession for a time nor for a number of steps is enough to demonstrate that a catch has occurred. A fielder may, for example, appear to catch and hold a batted ball securely, take a few more steps, collide with a wall or another player, and drop the ball—this is not a catch.
To avoid ambiguity with the common term catch meaning any action that gains possession of a ball, some may say that a fielder gloved a thrown ball or a batted, bouncing ball.
Baseball rules
