Running out the clock
In American football, each quarter of a game is measured with a 15-minute game clock, or 12-minute clock in many high school football codes and the German Football League. A team in possession of the lead and the ball will attempt to use up as much of the game clock as possible in order to bring the game to an end more quickly, thus denying the opposition another chance on offense.
Arena football
Coaches are given 2 (two) challenges per game, as in the NFL; to do so, they must throw the red flag before the next play. If the play stands as called after the play is reviewed they lose a timeout; however, if the play is reversed they keep their timeouts. If a team wins two straight challenges they are granted a third. All challenges are automatic in the final minute of each half and all overtime periods, as they are on all scoring plays and turnovers.