, ball (Infield Fly): Before two outs , a second base runner or first, second and third have runner hitter , hit a fly ball in the sector (excluding flat fly ball ) , and infielder can catch the ball in normal fielding the ball to the infield fly ball . Pitcher , catcher , and approached to within Nakano defensive outfielder , are regarded as an infielder . When hit out of the ball , obviously become the infield fly ball , the trial timely declaration of ' infield fly ball , the sector ball hit run members out ' ( Infield, a fly , the if fair , the batter is out . ) Infield fly ball situation during the race runner tread base and advance the principles , guidelines and general fly ball caught . If the infield fly ball is a foul ball, deemed out of bounds situation processing . The infield fly ball without touching, falling on the ground to form a bouncing ball , according to the criterion of the sector within the foul ball to determine the ball , determination is bounded ball , the infield fly ball rules apply , which is said to hit runner out .