Infield Fly Rule

Infield Fly Rule

The purpose of the infield fly rule is to prevent the defense from intentionally dropping an easy fly ball, and by doing so, getting a double -- or even triple play.
 
For the infield fly rule to be in effect, there must be less than two outs, with either first and second base occupied, or with bases loaded.
 
In this example, with one out … and runners at first and second, the batter hits a pop fly. … Even though the infielder has to go into the outfield grass to make the catch, the umpire believes the ball can be caught with ordinary effort, so he signals infield fly. … When an infield fly is caught, runners must tag up before advancing, or they may be called out on appeal.
 
The batter is still automatically out, however, even if the fielder does not catch the pop fly, as in this case. … The ball is not caught by the second baseman, but the runners are not forced to advance because the batter is already out. ... The runners may advance at their own risk and could be tagged out.
 
Whether or not the ball can be caught with ordinary effort by an infielder (including the pitcher and catcher, for the purposes of this rule) is up to the umpire’s judgment. … As a result, it is possible, in an infield fly situation, to have a pop-up that comes down on the infield … but is NOT ruled an infield fly.