Football

Football Overview• 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. The ball can be advanced by running 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. Team with the most points wins.

History of Football• American football resulted from several major divergences from rugby football, most notably the

rule changes instituted by Walter Camp, considered the "Father of American Football". • The popularity of collegiate football grew as it became the dominant version of the sport for the first

half of the twentieth century.• The origin of professional football can be traced back to 1892, with William Heffelfinger's $500

contract to play in a game for the Allegheny Athletic Association against the Pittsburgh Athletic Club. The first Professional "league" was the Ohio League, formed in 1903, and the first Professional Football championship game was between the Buffalo Prospects and the Canton Bulldogs in 1919.

• In 1920, the American Professional Football Association was formed. The first game was played in Dayton, Ohio on October 3, 1920 with the host Triangles defeating the Columbus Panhandles 14–0.

• The league changed its name to the National Football League (NFL) two years later, and eventually became the major league of American football.

• Football's increasing popularity is usually traced to the 1958 NFL Championship Game, a contest that has been dubbed the "Greatest Game Ever Played".

• A rival league to the NFL, the American Football League (AFL), began play in 1960; the pressure it put on the senior league led to a merger between the two leagues and the creation of the Super Bowl, which has become the most watched television event in the United States on an annual basis.

Football Field• American football is played on a field 360 by 160 feet. • 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 apart. A scoring area called an end zone extends 10 yards 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.

• Two rows of short lines, known as inbounds 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.

• At the back of each end zone are two goalposts (also called uprights) connected by a crossbar 10 feet from the ground.

Football Players

• Each team has 11 players on the field at a time. Usually there are many more players off the field (an NFL team has a limit of 53 players on their roster). However, teams may substitute for any or all of their players during the breaks between plays. As a result, players have very specialized roles and are divided into three separate units: the offense, the defense and the special teams.

Offense

• Offense• 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 quarterback (QB) receives the snap from the center on most plays. He then hands or tosses it to a running back, throws it to a receiver or runs with it himself. The quarterback is the leader of the offense and calls the plays that are signaled to him from the sidelines.

• Running backs (RB) line up behind or beside the QB and specialize in running with the ball. They also block, catch passes and, on rare occasions, pass the ball to others or even receive the snap. If a team has two running backs in the game, usually one will be a halfback (HB) (or tailback (TB)), who is more likely to run with the ball, and the other will usually be a fullback (FB), who is more likely to block.

• Wide receivers (WR) line up near the sidelines. They specialize in catching passes, though they also block for running plays or downfield after another receiver makes a catch.

• Tight ends (TE) line up next to the offensive line. They can either play like wide receivers (catch passes) or like offensive linemen (protect the QB or create spaces for runners). Sometimes an offensive lineman takes the tight end position and is referred to as a tackle eligible.

• At least seven players must line up on the line of scrimmage on every offensive play. The other players may line up anywhere behind the line. The exact number of running backs, wide receivers and tight ends may differ on any given play. For example, if the team needs only one yard, it may use three tight ends, two running backs and no wide receivers. On the other hand, if it needs 20 yards, it may replace all of its running backs and tight ends with wide receivers.

Defense

• Defense• In contrast to members of the offense, the rules of professional football and American college

football do not specify starting position, movement, or coverage zones for members of the defensive team, except that they must be in the defensive zone at the start of play. The positions, movements and responsibilities of all defensive players are assigned by the team by selection of certain coverages, or patterns of placement and assignment of responsibilities. The positional roles are customary. These roles have varied over the history of American football. The following are customary defensive positions used in many coverages in modern American football.

• 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.

• Behind the defensive line are the linebackers. They line up between the defensive line and defensive backs and may either rush the quarterback or cover potential receivers.

• The last line of defense is known as the secondary, comprising at least three players who line up as defensive backs, who are either cornerbacks or safeties. They cover the receivers and try to stop pass completions. They occasionally rush the quarterback.

Special Teams

• Special teams• 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.

Game Duration

• Game duration• 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 12-minute half-time intermission after the second quarter. At all levels, a down (play) that begins before time expires is allowed to continue until its completion, even after the clock reaches zero. The clock is also 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 television, TV timeouts are taken at certain intervals of the game to broadcast commercials outside of game action. If an NFL game is tied after four quarters, the teams play an additional period lasting up to 15 minutes.

Scoring

• Touchdown: When a player keeps possession of the ball over the goal line he is awarded 6 points.

• Extra Point: After a touchdown is scored the scoring team gets to attempt a short field goal for one extra point.

• Two Point Conversion: After a touchdown is scored a team can opt to run one play from the 2 yard line in order to score two points instead of the extra point kick try.

• Field Goal: A field goal is worth 3 points and is scored when a kicker successfully kicks the football through the uprights.

• Safety: A safety is worth two points and is scored when the offense commits a penalty in their own end zone or when they cannot advance the ball out of the end zone before being tackled.

Penalties 1False Start• When an offensive player already set for the snap moves or flinches before the snap of the ball, this is called a false start. It

is more commonly known as offsides. The play is over and a five yard penalty is assessed.Illegal Procedure• Offensive skill position players can move parallel to the line of scrimmage before the snap of the ball. One at a time can

move perpendicular to the line before the ball is snapped. These players must be set for one second before the snap. If a player moves without setting properly before the snap of the ball, or if that player is moving perpendicular to the line of scrimmage when the ball is snapped, then an illegal procedure penalty is called. This is a five yard penalty.

Encroachment• When a defensive player moves across the line of scrimmage and does not return to his side of the ball before the snap, this

is called encroachment. If a defensive player crosses the line of scrimmage and this causes a set offensive player to move, this is also considered encroachment. This is a five yard penalty on the defense, with a replay of the down. The offense can decline this penalty, if the gain on the play is more advantageous.

Holding• When an offensive player grabs part of the jersey of a defensive player, then offensive holding is called. Also, if an offensive

player grabs the arms of a defender (or does not keep his arms inside the arms of the defender), or if the offensive player wraps an arm around a defender, then offensive holding is called. This is a ten yard penalty, with the down being replayed.

• Defensive holding can also occur. If this happens, then it is a five yard penalty and an automatic first down.

Penalties 2Chop Blocking• If an offensive player is engaged in a block of a defender, then another offensive player blocks the same defender below the

waist, this is called a chop block. A fifteen yard penalty is assessed against the offense.• The chop block is considered a particularly dirty play, because defenders view it as a deliberate attempt to cause them a

knee injury. More than one fight has started over perceived chop blocks.Illegal Block in the Back• When an offensive player blocks a defender from behind, an illegal block in the back occurs. A ten yard penalty is assessed.

There is a gray area with these blocks, because some blocks from the side also are called. Typically, if a player blocks another player outside of the front shoulder pads, it is possible for an illegal block in the back to be called.

Delay of Game• In the pro game, there is a 45 second clock between plays. Therefore, if the offense does not snap the ball before the 45

seconds are up, then a delay of game penalty is called. This is a five yard penalty.Face Mask• When one player grabs the face mask of an opponent, this is a five yard penalty.• When a player grabs the face mask of an opponent and uses it to tackle or otherwise manhandle that opponent, a fifteen

yard penalty is assessed.

Penalties 3Illegal Contact • This is similar to pass interference, though the penalty assessed is only five yards and an automatic first down. This is when

a defender makes contact with a receiver like in pass interference, but before the football is in the air.Running Into the Kicker• On a punt, if a player from the receiving team runs into the kicker while his leg is still in the air, then a running into the

kicker penalty is called. This is a five yard penalty.• If that player is pushed into the punter by one of the punter’s teammates, then no penalty is called. Also, if the offending

player gets his hand on the ball, no penalty is called. Also, if the balls hits the ground before the punter catches it to punt it, no penalty is called.

• If a player who runs into the punter is deemed to be deliberately running into the kicker, a "roughing the kicker" penalty is called. This is a fifteen yard penalty and an automatic first down.

Unsportsmanlike Conduct• If one player strikes an opponent with a fist or kick, runs into a player after the whistle is blown, or jumps on the pile after

the whistle is blown, then a player is called for an unsportsmanlike conduct penalty. If a player taunts an opponent by spiking the ball in his face, or some other flagrant act, then an unsportsmanlike conduct penalty is called. These penalties are worth fifteen yards.

Kickoffs Out of Bounds• If a kickoff is kicked out of bounds, then the receiving team gets the ball on their 40 yard line automatically.Intentional Grounding• Intentional grounding happens when a quarterback get rid of the ball in order to avoid a sack. The play is whistled dead

(ended) and a penalty is assessed from the spot of the foul. Also, the offense loses a down.

Other Football Terms

• Interception: When the defense catches a ball thrown by the opposing quarterback.

• Fumble: When the player carrying the football loses possession of it.

• Sack: When the quarterback is tackled behind the line of scrimmage with the football.