How the umpire checks it
- Check the number of outs. With two outs, there is no infield fly.
- Check the runners. It only applies with runners on first and second, or bases loaded.
- Judge the batted ball. It must be a fair fly ball, not a line drive or bunt.
- Decide whether an infielder could catch it with ordinary effort.
- If all of that is true, the umpire calls infield fly and the batter is out whether the ball is caught or not.