What it is

A pump fake is a motion in which the quarterback brings the ball forward as if to throw, but holds it, hoping a defender reacts to the fake.

In a game

If a defensive back jumps at the fake, the receiver behind him is open. It can also freeze a pass rusher for a moment.

More detail

The quarterback must sell the fake with his whole body, and then reset his feet to throw. It is a favorite against defenders who are very aggressive on short routes.

Animated diagram

1. The quarterback drops back and brings the ball up as if to throw to the short receiver.
2. The defensive back sees the motion and jumps at the short route.
3. The quarterback holds the ball and throws to the receiver who is now open behind him.