American football
American football is a sport which was invented in the United States of America, where it is generally just called football, and is often called Grid Iron. It was originally based on Rugby and is one of 3 types of football that are unique to an individual country, alongside Australia's Australian Rules football and Ireland's Gaelic football. It is most similar to Australian Rules football. It uses an oval shaped ball.
Origins of American football[edit]
American football is based on rugby and came about during the separation of rugby between Rugby Union and Rugby League, initiated simultaneously in Great Britain and Australia, which in turn was also the timing of the creation of Australian Rules football, though it was also influenced by changes in rules for soccer.
American football took the Rugby League route of having more stoppages but went further to have far more stoppages than Rugby League did, including the notion of incomplete passes. They also took the route that Australian Rules football had in having less violent play and went further by introducing a large range of protective equipment. As such, American football has more stoppages than any other form of football anywhere in the world and also is less violent with less injuries than any other form of Rugby-based football (though still more injuries than soccer). It is thus a relatively safe game with many breaks in between exciting movements.
The game became professional in 1892 with the first truly professional league beginning in 1920. It was thus comparable with the timing and formation of Australian Rules football, which is the game which is most similar to it anywhere in the world.