American football, known in the United States simply as football and sometimes as gridiron outside the United States and Canada, is a sport played between two teams of eleven. The objective of the game is to score points by advancing the ball into the opposing team's end zone. The ball can be advanced by running with it or throwing it to a teammate. Points can be scored by carrying the ball over the opponent's goal line, catching a pass thrown over that goal line, kicking the ball through the opponent's goal posts or tackling an opposing ball carrier in his own end zone.
American football is closely related to Canadian football but with some differences in rules and in the configuration of the field, in particular the presence of eleven players on the field rather than twelve and the allowance of four downs per possession rather than just three. The larger number of downs results in more offensive rushing in American football than in the Canadian game.
In the United States, the major forms are high school football, college football and professional football, which are essentially similar but feature slightly different rules.
The history of American football can be traced to early versions of rugby football and association football. Both games have their origins in varieties of football played in the United Kingdom in the mid-19th century, in which a ball is kicked at a goal and/or run over a line. Many games known as "football" were being played at colleges and universities in the United States in the first half of the 19th century.
American Football HUH?
