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.
American football rules
If a game is tied at the end of four quarters, "overtime" is played. In overtime, the coin is tossed to determine which team will possess the ball first. The winner of the coin toss can choose to give the ball or receive the ball. If the first possession results in a field goal, the other team is given possession to match or better the field goal; therefore continuing the game. If the first possession results in a touchdown or safety, the scoring team wins. During the regular season in the NFL, one overtime period is played (with each team receiving two time outs). If both teams are tied after the 10-minute overtime, the game officially ends in a tie. In the playoffs, 15-minute overtime periods continue until a winner is determined. Overtime follows a three-minute intermission after the end of the regulation game. Prior to start of overtime, a coin flip is performed in which the captain of the visiting team calls the toss. The team that wins the coin flip has the option either to receive the kickoff or choose the side of the field they wish to defend. Ties are rare in the NFL; a game between the Minnesota Vikings and Green Bay Packers on September 16, 2018 ended in a 29–all draw. The previous occurrence was one week earlier, on September 9, 2018.