Football Helmet Protective pads
Each team has 11 players on the field at a time. However, teams may substitute for any or all of their players, if time allows, during the break between plays. The game begins with a coin toss to determine who will kick off to begin the games and which goal each team will defend. A standard football game consists of four 15-minute quarters (12-minute quarters in high-school football and often shorter at lower levels), with a half-time intermission after the second quarter. Once a team gains possession of the ball, that team becomes the offensive team and must advance the ball. Players can then advance the ball in two ways: by running with the ball, also known as rushing, or by throwing the ball to a teammate. The offense can throw the ball forward only once during a down and only from behind the line of scrimmage. The ball can be thrown, pitched, handed-off, or tossed sideways or backwards at any time. A team scores by advancing the ball into the opposing team's endzone. Change of possession can occur on a turnover, a loss of down when the offense fails to gain a new set of down, a punt, or by scoring. There are a number of other rules governing the game, some differing between the various levels of play.
Tackle Football is another name for American football. American football is a game played by two teams of players, eleven on both offense and defense, on a filed measuring a hundred yards long. The offensive team has four downs to either advance the ball ten yards to gain a new set of downs, or score by advancing the ball into the opposing team's endzone. The defensive team attempts to stop the offensive team from scoring, or gaining a new set of downs in order to get possession of the ball.
Tackle, or American, football is a sport with roots in rugby and soccer. Football diverged from rugby through the rule changes initiated by Walter Camp, considered as the "Father of American Football." Among these important rule changes were the introduction of the line of scrimmage and of down-and-distance. In the late 19th and early 20th centuries, gameplay developments by Knute Rockne, and Glenn "Pop" Warner helped take advantage of the newly introduced forward pass. The popularity of collegiate football grew as it became the dominant version of the sport for the first half of the twentieth century. Bowl games, a college football tradition, attracted a national audience for collegiate teams. The origin of professional football can be traced back to 1892, with William "Pudge" Heffelfinger's $500 contract to play in a game for the Allegheny Athletic Association against the Pittsburgh Athletic Club. In 1920 the American Professional Football Association was formed. This league changed its name to the National Football League (NFL) two years later, and eventually became the major league of American football.