How does the coaches' challenege of a play work?

Answer 1

The coach on either team can throw a "red" challenge flag if they feel that the ref's call on the field is in error.This goes for defense or offense. If the call is reversed to in fact be in favor of the challenging coach, then the ref's decision on the field is overruled and there is no further action. If the call on the field stands (does not reverse due to the challenge of the coach), then the challenging coach is charged a timeout. A coach is only allowed two challenges per half of a football game.