What is the purpose and application of the Major League Baseball infield fly rule?

Answer 1

The purpose of the Major League Baseball infield fly rule is to prevent the defense from intentionally dropping a pop-up to create a double play opportunity. This rule applies when there are runners on first and second base (or bases loaded) with less than two outs, and a fair fly ball can be caught by an infielder with ordinary effort. If the umpire calls an infield fly, the batter is automatically out, regardless of whether the ball is caught, and the runners can advance at their own risk.