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.
List of gridiron football rules
Scoring and game timing are much different in touch football than its more organized counterpart. For the sake of simplicity, touchdowns are usually worth 1 point and no other scoring is counted (there are no extra point attempts). In a much lesser used variation, a touchdown is worth 6 points and if the player who scored the touchdown can progress in the other direction from the end zone in which he had just scored back to the opposite end zone without being touched, it counts as a two-point conversion. The former scoring method does not allow for other scoring types such as safeties. There is usually no game clock and the game ends when one opponent has reached 10 touchdowns (in the former convention) or 100 points (in a standard convention).The NFL adopted many ideas introduced by the AFL, including names on player jerseys and revenue sharing of gate and television receipts. The older league also adopted the practice of using the stadium scoreboard clocks to keep track of the official game time, instead of just having a stopwatch used by the referee. The AFL played a 14-game schedule for its entire existence, starting in 1960. The NFL, which had played a 12-game schedule since 1947, changed to a 14-game schedule in 1961, a year after the American Football League instituted it; it has been 16-game seasons since 1978. The AFL also introduced the two-point conversion to professional football thirty-four years before the NFL instituted it in 1994 (college football had adopted the two-point conversion in the late 1950s). All of these innovations pioneered by the AFL, including its more exciting style of play and colorful uniforms, have essentially made today's pro football more like the "AFL" than like the old-line NFL. The AFL's challenge to the NFL also laid the groundwork for the Super Bowl, which has become the standard for championship contests in the United States.