Rules of the game:
American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team’s end zone
Known in the United States simply as football, it may also be referred to informally as gridiron football
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. Both sports can be traced to early versions of association football and rugby football.
Football is played on a field 360 by 160 feet (120.0 by 53.3 yards)
The longer boundary lines are sidelines, while the shorter boundary lines are end lines. Sidelines and end lines are out of bounds.
Near each end of the field is a goal line, they are 100 yards (91.4 m) apart.
A scoring area called an end zone extends 10 yards (9.1 m) beyond each goal line to each end line. The end zone includes the goal line but not the end line.
Yard lines cross the field every 5 yards, and are numbered every 10 yards from each goal line to the 50-yard line, or midfield (similar to a typical rugby league field).
Two rows of short lines, known as in-bounds lines or hash marks, run at 1-yard intervals perpendicular to the sidelines near the middle of the field.
All plays start with the ball on or between the hash marks. Because of the arrangement of the lines, the field is occasionally referred to as a gridiron.
At the back of each end zone are two goalposts (also called uprights) connected by a crossbar 10 feet from the ground.
Each team has 11 players on the field at a time.
Players have very specialized roles and are divided into three separate units: the offense, the defense and the special teams.
The offensive line (OL) consists of five players whose job is to protect the passer and clear the way for runners by blocking members of the defense.
The lineman in the middle is the center. Outside the center are the guards, and outside them are the tackles. Except for the center, who snaps the ball to one of the backs, offensive linemen generally do not handle the ball.
The defensive line consists of three to six players who line up immediately across from the offensive line. They try to occupy the offensive linemen in order to free up the linebackers, disrupt the backfield (behind the offensive line) of the offense, and tackle the running back if he has the ball before he can gain yardage or the quarterback before he can throw or pass the ball. They are the first line of defense.
The units of players who handle kicking plays are known as special teams. Three important special-teams players are the punter, who handles punts, the placekicker or kicker, who kicks off and attempts field goals and extra points, and the long snapper, who snaps the ball for extra points, field goals, and punts.
Also included on special teams are the returners. These players return punts or kickoffs and try to get in good field position. These players can also score touchdowns.
A standard football game consists of four 15-minute quarters, with a half-time intermission after the second quarter.
The clock is stopped after certain plays, therefore, a game can last considerably longer (often more than three hours in real time), and if a game is broadcast on TV.
If an NFL game is tied after four quarters, the teams play an additional period lasting up to 15 minutes.
As of the 2012 season, if the first team with possession does not score a touchdown on the initial possession, the other team is given a possession.
If the score is still tied after both teams have had a possession, then the old sudden death rules go into effect. If neither team scores in overtime, the game is a tie.
Advancing the ball
The team that takes possession of the ball (the offense) has four attempts, called downs, in which to advance the ball at least 10 yards toward their opponent’s (the defense’s) end zone.
When the offense succeeds in gaining at least 10 yards, it gets a first down, meaning the team starts a new set of four downs to gain yet another 10 yards or to score.
If the offense fails to gain a first down (10 yards) after four downs, the opposing team gets possession of the ball at the point where the fourth down ended, beginning with their first down to advance the ball in the opposite direction.
Players can then advance the ball in two ways:
1.By running with the ball, also known as rushing.
2.By throwing the ball to a teammate, known as a pass or as passing the football.
Players can then advance the ball in two ways:
1.By running with the ball, also known as rushing.
2.By throwing the ball to a teammate, known as a pass or as passing the football.
If the pass is thrown down-field, it is known as a forward pass. The offense can throw the ball forward only once during a down and only from behind the line of scrimmage. However, the ball can be handed-off to another player or thrown, pitched, or tossed sideways or backwards (a lateral pass) at any time.
A down ends, and the ball becomes dead, after any of the following:
• The player with the ball is forced to the ground or has his forward progress halted by members of the other team.
• A forward pass flies beyond the dimensions of the field (out of bounds) or touches the ground before it is caught. This is known as an incomplete pass. The ball is returned to the most recent line of scrimmage for the next down.
• The ball or the player with the ball goes out of bounds.
• A team scores.
Change of possession
The offense maintains possession of the ball unless one of the following things occurs:
• The team fails to get a first down, i.e. in four downs they fail to move the ball past a line 10 yards ahead of where they got their last first down. The defensive team takes over the ball at the spot where the 4th-down play ends. A change of possession in this manner is commonly called a turnover.
• The offense scores a touchdown or field goal. The team that scored then kicks the ball to the other team in a special play called a kickoff.
• The offense punts the ball to the defense. A punt is a kick in which a player drops the ball and kicks it before it hits the ground. Punts are nearly always made on fourth down, when the offensive team does not want to risk giving up the ball to the other team at its current spot on the field (through a failed attempt to make a first down) and feels it is too far from the other team’s goal post to attempt a field goal.
• A defensive player catches a forward pass. This is called an interception, and the player who makes the interception can run with the ball until he is tackled, forced out of bounds, or scores.
• An offensive player drops the ball (a fumble) and a defensive player picks it up. As with interceptions, a player recovering a fumble can run with the ball until tackled, forced out of bounds, or scoring.
• Passes that are thrown either backwards or parallel with the line of scrimmage (lateral passes) that are not caught do not cause the down to end as incomplete forward passes do; instead the ball is still live as if it had been fumbled. Lost fumbles and interceptions are together known as turnovers.
• The offensive team misses a field goal attempt. The defensive team gets the ball at the spot where the previous play began.
• While in his own end zone, an offensive ball carrier is tackled, forced out of bounds, loses the ball out of bounds, or the offense commits certain fouls in the end zone. This fairly rare occurrence is called a safety.
• An offensive ball carrier fumbles the ball forward into the opposing end zone, and then the ball goes out of bounds. This rare occurrence leads to a touch back, with the ball going over to the opposing team at their 20 yard line (Note that touch backs during non-offensive special teams plays, such as punts and kickoffs, are quite common).
Scoring
A team scores points by the following plays:
• A touchdown TD) is worth 6 points. It is scored when a player runs the ball into or catches a pass in his opponent’s end zone. A touchdown is similar to a try in rugby. However, unlike rugby, a player does not have to touch the ball to the ground to score; a touchdown is scored any time a player has possession of the ball while any part of the ball is beyond the vertical plane created by the leading edge of the opponent’s goal line stripe (the stripe itself is a part of the end zone).
• After a touchdown, the scoring team attempts a try (similar to the rugby conversion). The team can attempt to kick it through the goalposts (over the crossbar and between the uprights) in the manner of a field goal for 1 point, or run or pass it into the end zone in the manner of a touchdown for 2 points.
• A field goal (FG) is worth 3 points, and it is scored by kicking the ball through the goalposts defended by the opposition. A field goal is usually attempted on fourth down instead of a punt when the ball is close enough to the opponent’s goalposts, or, when there is little or no time left to otherwise score.
