Football is known as American football in Canada and the United States is a competitive team sport played by millions of people. The object of the game is to score points by advancing the football towards the team opposing end of the field. The ball can be thrown, or carrying the ball to the other end. Points can be scored by kicking threw goals posts or carrying it over the goal line. The winner is decided on who has the most points at the end of the game. The game originates from versions of Rugby played in England. It was in introduced by the British army in Montreal, Canada. The first inter collegiate game was between Rutgers and Princeton Universities on November 6, 1869.

Rules

A team is often comprised of 11 players on the field at a time. Football is played within a time limit of 4 15 minute quarters. Within that time limit teams must play to score more points then the opposing team. The total length of the field is 120 yards by 53 1/3 yards wide. A score is made by a team by crossing the goal line and advancing the ball across goal line and carrying the ball into the end zone. This is called a touchdown and is worth 6 points. A team also has 4 (downs) opportunities in American football and 3 opportunities (downs) to advance the ball 10 yards to receive a first down (another set of opportunities) to advance the ball again, until the team crosses the goal line and scores a touchdown worth 6 points. If a team does not advance the ball 10 yards within a matter of 10 downs, then a team must turn over the ball to the other team.

Other points are scored by kicking the ball through the goal posts. A field goal is scored often when a team cannot score a touchdown with and is on there last down and they are in jeopardy of turning the ball over to the other team. If they are close enough to kick the ball through the opposing teams' goal posts then a team will often kick a field goal. An extra point is also attempted after a team scores a touchdown by kicking the ball through the opposing teams' goals posts or by attempting to cross the ball over the end zone. A kick is worth 1 point while crossing the goal line again after a team scores a touchdown is worth 2 points. A safety is worth 2 points. A safety is scored by the defense when the offensive player in possession of the ball is forced back into his own end zone and is tackled there, or fumbles the ball out of the end zone, or commits intentional grounding in the end zone.

Types of players

Offense

• The offensive line consists of five players whose job is to protect the passer and clear the way for runners by blocking members of the defense. Except for the center, offensive linemen generally do not handle the ball.
• The quarterback (QB) receives the ball on most plays. He then hands or tosses it to a running back, throws it to a receiver or runs with it himself.
• Running backs line up behind or beside the QB and specialize in rushing with the ball. They also block, catch passes and, on rare occasions, pass the ball to others.
• Wide receivers line up near the sidelines. They specialize in catching passes.
• Tight ends line up outside the offensive line. They can either play like wide receivers (try to catch passes) or like offensive linemen (protect the QB or create spaces for runners).

Defense

• The defensive line consists of three to five players who line up across from the offensive line. They try to tackle the running backs before they can gain yardage or the quarterback before he can throw a pass.
• At least three players line up as defensive backs. They cover the receivers and try to stop pass completions. They occasionally rush the quarterback.
• The other players on the defense are known as linebackers. They line up between the defensive line and defensive backs and may either rush the quarterback or cover potential receivers.