American Football, simply football in the United States and Canada, is a team sport where two teams of eleven players advance an oval-shaped football down a rectangular field to score points. The football is moved by the team on offense through designed running or passing plays, while the defense attempts to stop their momentum. The offense must successfully gain ten yards in four plays or the ball is turned over to the defending team. Points are scored when one team moves the ball into the opposing team’s end zone, resulting in a touchdown (six points), by kicking the ball through the field goal post (three points, one extra point after a touchdown), or by tackling the offense inside their own end zone resulting in a safety (two points). The NFL (National Football League) is the professional league in the United States.
The American Football regular season begins every year on the weekend that follows the first Monday of September. This occurs yearly as the weekend following the American Labor Day Holiday.
The average American Football game lasts for 3 hours and 12 minutes. Although the official game clock of a football game is only four quarters at 15 minutes each (60 minutes total), the clock is stopped after any incomplete pass, when a player with the ball steps out of bounds, or when a timeout is called.
American Football is played with a maximum of 11 players from each team on the field at a single time. Each team is allowed to maintain a roster of up to 45 players of different skills, sizes, and roles that can be substituted into the game at any time.