Overview
The infield fly rule applies with fewer than two outs and runners on first and second or bases loaded. When a fair fly ball (excluding line drives and bunts) can be caught by an infielder with ordinary effort, the umpire declares 'infield fly' and the batter is automatically out regardless of whether the ball is actually caught. This rule prevents infielders from intentionally dropping pop-ups to turn double or triple plays against frozen baserunners. Runners must tag up if the ball is caught but may advance at their own risk if it is dropped-crucially, the force play is removed. In NPB, the rule occasionally sparks debate, particularly on windy days when pop flies drift or when balls land in the gray area between infielders and outfielders, making the umpire's judgment call difficult. Misunderstanding this rule can lead to costly baserunning errors, making it essential knowledge for all players.