[1] When a catch occurs, the batter is out (said to have flied out), and runners are in jeopardy of being put out if any fielder with possession of the ball reaches their starting base before they do.
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.
If the fielder uses their cap, protector, pocket or any other part of their uniform in getting possession, it is not a catch.
A catch is legal if the ball is finally held by any fielder before it touches the ground.
A fielder may reach over a fence, a railing, a rope, or a line of demarcation to make a catch.