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For the musical group, see American Football (band).

American football, known in North America simply as football, is a competitive team sport. The object of the game is to advance the football towards the opposing team's end zone and score points. The ball can be advanced by carrying the ball, or by throwing or handing it from one teammate to the other. Points can be scored in a variety of ways, including carrying the ball over the goal line, throwing the ball to another player past the goal line or kicking it through the goal posts. The winner is the team with the most points when the time expires.

Outside of the United States, Canada, and a few other countries such as American Samoa, the sport is usually referred to as American football (or sometimes as gridiron) to differentiate it from other football games, especially association football and rugby football. American football evolved as a separate sport from rugby football in the late 19th century. Arena football is a variant of American football.

Contents 1 Popularity 2 The rules of American football 2.1 Field and players 2.2 Game duration 2.3 Advancing the ball 2.4 Changes of possession 2.5 Scoring 2.6 Kickoffs and free kicks 2.7 Penalties 3 The players 3.1 Offense 3.2 Defense 3.3 Special teams 4 Basic football strategy 5 Development of the game 6 Problems in football 7 Professional, college, and other leagues 8 References 9 See also 10 External links

Popularity

Since the 1960s, football has surpassed baseball as the most popular spectator sport in the United States. The 32-team National Football League (NFL) is the most popular and only major professional American football league. Its championship game, the Super Bowl, is watched by nearly half of US television households, and is also televised in over 150 other countries. Super Bowl Sunday has become an annual ritual in late January or early February. It is also the most watched sport on television in the US.

The NFL also operates a developmental league, NFL Europe, with 6 teams based in European cities.

College football is also extremely popular throughout the U.S., especially in markets not served by an NFL team. Several college football stadiums seat more than 100,000 fans -- which regularly sell out. Even high school football games can attract five-figure crowds, especially in hotbeds like Western Pennsylvania, Ohio, Florida, Texas and Georgia. The weekly autumn ritual of college and high-school football -- which includes marching bands, cheerleaders and parties -- is an important part of the culture in much of smalltown America.

Football is also played recreationally by amateur club and youth teams (e.g., the Pop Warner little-league programs). There are also many "semi-pro" teams in leagues where the players are paid to play, but at a small enough salary that they generally must also hold a full-time job.

Organized football is played almost exclusively by men and boys.

The rules of American football

Objective: Like most other games of football, the object of American football is to advance the ball towards the opponent's end of the field and score more points than the opposing team within a set time limit.

Field and players

The American football field is often called the gridiron because the markings on the field resemble that type of grill that can be used to cook food over a fire. The game is played on a rectangular field 120 yards (110 metres) long by 53 1/3 yards (49 metres) wide. The longer boundary lines are sidelines, while the shorter boundary lines are end lines. 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.

Yard lines cross the field every 5 yards, and are numbered from each goal line to the 50-yard line, or midfield (similar to a typical rugby league field). Two rows of lines, known as hash marks parallel the side lines 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 goal posts (also called uprights) that are 18.5 feet apart. The posts are connected by a crossbar 10 feet from the ground. Successful kicks must go above the crossbar and between the uprights. (At many fields the uprights and crossbar are attached by a curved bar to a post outside the field of play, to reduce the chance of players running into the supports.)

Each team has 11 players on the field at a time. However, teams may substitute for any or all of their players between plays. As a result, players have very specialized roles, and almost all of the 53 players on an NFL team will play in any given game. Thus, teams are divided into three separate units: the offense, the defense and the special teams (see below).

Game duration

A standard football game consists of four 15-minute (typically 12 minutes in high school football) periods (called quarters), with an intermission (called halftime) after the second quarter. The clock stops after certain plays; therefore, a game can last considerably longer (often more than three hours in real time). If an NFL game is tied after four quarters, the teams play up to another 15 minutes. The first team that scores wins; if neither team scores, the game is a tie. College overtime rules are more complicated and are described at Overtime (sport).

Advancing the ball

Advancing the ball in American football resembles the six-tackle rule and the play-the-ball in rugby league football. The team that takes possession of the ball (the offense) has four attempts, called downs, to advance the ball 10 yards towards their opponent's (the defense's) end zone. When the offense gains 10 yards, it gets a first down, or another set of four downs to gain 10 yards. If the offense fails to gain a first down, it loses possession of the ball.

Except at the beginning of halves and after scores (see Kickoffs and free kicks below), the ball is always put into play by a snap. All players line up facing each other at the line of scrimmage (the position on the field where the play begins). One offensive player, the center, \then passes (or "snaps") the ball between his legs to a teammate, usually the quarterback.

Players can then advance the ball in two ways:

• By running with the ball, also known as rushing.
• By throwing the ball to a teammate, known as passing. The forward pass is a key factor distinguishing American and Canadian football from other football sports. The offense can throw the ball forward only once on a play and only from behind the line of scrimmage. The ball can be thrown sideways or backwards at any time. This type of pass is known as a lateral and is much rarer in American football than in rugby league or rugby union.

A play or down ends, and the ball becomes dead, after any of the following:

• The player with the ball is tackled to the ground by a member of the opposing team, or has his forward progress stopped (as determined by an official).
• A forward pass flies out of bounds or touches the ground before it is caught. This is known as an incomplete pass. The ball is returned to the original line of scrimmage for the next down.
• The ball or the player with the ball goes beyond the dimensions of the field (out of bounds).
• A team scores.

Often an official will blow a whistle to notify all players that the play is over.

At all times, players and fans must be aware of the sequence of downs and the distance to a new first down. When a team has a first down, the scoreboard or television screen flashes "1st and 10" — that is, first down and 10 yards to go. If the team gains three yards on the first play, the next down will be "2nd and 7."

Changes of possession

The offense maintains possession of the ball unless one of the following things happens:

• The team fails to get a first down, that is, move the ball forward at least 10 yards in four downs. The defensive team takes over the ball at the spot where the play ends. A change of possession in this manner is commonly called a turnover on downs.
• The offense scores a touchdown or field goal. The team that scored then kicks off the ball to the other team. (See Scoring and Kickoffs below.)
• 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 posts to kick 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 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 or forced out of bounds. 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 (or, in the NFL, at the spot of the kick). If the unsuccessful kick was attempted from very close to the end zone, the other team gets the ball at its own 20-yard line (that is, 20 yards from the end zone).
• An offensive player is tackled or forced out of bounds in his own end zone. This rare occurrence is called a safety. (See Scoring below.)

Scoring

A team scores points by the following plays:

• A touchdown (TD) is worth 6 points. A touchdown is scored when a player runs the ball into or catches a pass in his opponent's end zone.
  • After a touchdown, the scoring team attempts a conversion. The ball is placed at the other team's 3-yard-line (the 2-yard-line in the NFL). The team can attempt to kick it over the crossbar and through the goal posts for 1 point (an extra point), or run or pass it into the end zone for 2 points (a two-point conversion). In collegiate and professional leagues, the extra point is usually preferred; its success rate is 94% in the NFL and 93.8% in the NCAA, compared to 43% in the NFL and 43.5% in the NCAA for two-point conversions.
• A field goal (FG) is worth 3 points, and it is scored by kicking the ball over the crossbar and through the goal posts. Field goals must be placekicked, that is, kicked when the ball is held vertically against the ground by a teammate. A field goal is usually attempted on fourth down instead of a punt when the ball is close to the goal line.
• 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. Certain penalties by the offense occurring in the end zone also result in a safety.

Kickoffs and free kicks

Each half begins with a kickoff. Teams also kick off after scoring touchdowns and field goals. The ball is kicked from a kicking tee, which is made from one's own 30-yard line in the NFL and from the 35-yard line in college football. The other team's kick returner tries to catch the ball and advance it as far as possible. Where he is stopped is the point where the offense will begin its drive, or series of offensive plays. If the kick returner catches the ball in his own end zone, he can either run with the ball, or elect for a touchback by kneeling in the end zone. The receiving team can then start its offensive drive from its own 20-yard line. A touchback can also occur when the kick goes out of the end zone. Punts and turnovers in the end zone can also end in touchbacks. If a kickoff goes out of bounds over the sidelines without being interfered by the receiving team, the ball will be placed 30 yards from the spot of the kickoff (traditionally at the receiving team's 40-yard line in the NFL or the 35-yard line in college football).

After safeties, there is a free kick instead of a kickoff. A free kick is made from a team's own 20-yard-line and can be punted or placekicked.

Penalties

Rules violations are punished with penalties. Most penalties result in a loss of yards for the offending team. Some penalties on the defense give the offense an automatic first down. If a penalty occurs during a play, an official throws a yellow flag near the spot of the foul. When the play is over, the team that did not commit the penalty has the option of taking either the penalty or the result of the play. For example, say a defensive player commits an offsides penalty on first down by passing the line of scrimmage before the snap, and the offense gains eight yards on the play. The team with the ball has the option of taking the penalty and a new first down with five yards to go, or declining the penalty and scrimmaging with 2nd and 2.

The players

As noted above, most football players have highly specialized roles. At the college and NFL levels, most play only offense or only defense.

Offense

• The offensive line (OL) consists of five players (two offensive tackles (OT), two guards (G), and a center (C)) whose job is to protect the passer and clear the way for runners by blocking members of the defense. All plays begin with the center handing the ball backwards between his legs, or snapping it, to a teammate, usually the quarterback.
• 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 (RB) 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. There are two main kinds of running backs: fullbacks (FB), who usually block, and halfbacks or tailbacks, who are more likely to carry the ball.
• Wide receivers (WR) line up near the sidelines. They specialize in catching passes.
• Tight ends (TE) 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).

Not all of these types of players will be in on every offensive play. Teams can vary the number of wide receivers, tight ends and running backs on the field at one time.

Defense

• The defensive line (DL) consists of three to five players (two defensive ends, one or two defensive tackles (DT), and possibly one nose guard (DT)) 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 four players line up as defensive backs (DB). They may be cornerbacks (CB), free safeties (FS), or strong safeties (SS). They cover the receivers and try to stop pass completions. They occasionally rush the quarterback. However, in high school, it is not uncommon to see a team go without the addition of a strong safety, due to the inexperience of high school quarterbacks and wide receivers.
• The other players on the defense are known as linebackers (LB). They line up between the defensive line and backs and may either rush the quarterback or cover potential receivers. They are split up into two different types, middle linebackers and outside linebackers.

Special teams

The units of players who handle kicking plays are known as special teams. Special-teams players include the punter (P), who handles punts, and the placekicker or kicker (PK or K), who kicks off and attempts field goals and extra points. Field goal and extra point attempts also require a holder who receives the ball from the center and holds it in a position that allows the kicker to easily kick the ball. The holder is usually a backup quarterback, as the field goal formation is very occasionally used for a pass or run play instead in a last-ditch effort to get a first down or touchdown, called a fake field goal. Kickers have also (very rarely) been known to take the snap and run a fake field goal play themselves.

Basic football strategy

Main article: American football strategy

To many fans, the chief draw of football is the chess game that goes on between the two coaching staffs. Each team has a playbook of dozens to hundreds of plays. Plays are the directions for what the players should do on a down. Some plays are very safe; they are very likely to get a few yards, but not much more than that. Other plays have the potential for long gains but a greater risk of a loss of yardage or a turnover.

Generally speaking, rushing plays are less risky than passing plays. However, there are relatively safe passing plays and risky running plays. To fool the other team, there are passing plays designed to look like running plays and vice versa. There are many trick or gadget plays, such as when a team lines up like it is going to kick and then tries to run or pass for a first down. Such high-risk plays are a great thrill to the fans when they work. However, they can spell disaster if the opposing team realizes the deception and acts accordingly.

It has been said that football is the closest sport that strategically resembles real war, which may explain why it is by far the most popular sport in the American military. In fact, the United States Military Academy, the United States Naval Academy, and the United States Air Force Academy each field football teams that participate in Division I-A of the NCAA. Army and Navy have a particularly historic rivalry.

Development of the game

For more details on this topic, see History of American football.

Both American football and soccer have their origins in varieties of football played in the United Kingdom in the mid-19th century, and American football is directly descended from rugby football.

Rugby was first introduced to North America in Canada, brought by the British Army garrison in Montreal which played a series of games with McGill University. Both Canadian and American football evolved from this point. For an in-depth overview of the differences and similarities of Canadian football and American football see: Comparison of Canadian and American football

American colleges spearheaded the growth of football. The first inter-collegiate football game was played between Rutgers and Princeton Universities on November 6, 1869. The game was won by Rutgers (6-4) although "The game, which bore little resemblance to its modern-day counterpart, was played with two teams of 25 men each under rugby-like rules, but like modern football, it was “replete with surprise, strategy, prodigies of determination, and physical prowess,” to use the words of one of the Rutgers players." - Rutgers Football

American football in its current form grew out of a series of three games between Harvard University and McGill University of Montreal in 1874. McGill played rugby football while Harvard played the Boston Game, which was closer to soccer. As often happened in those days of far from universal rules, the teams alternated rules so that both would have a fair chance. The Harvard players liked having the opportunity to run with the ball, and in 1875 persuaded Yale University to adopt rugby rules for their annual game. In 1876 Yale, Harvard, Princeton, and Columbia formed the Intercollegiate Football Association, which used the rugby code, except for a slight difference in scoring.

In 1880 Walter Camp introduced the scrimmage in place of the rugby scrum. In 1882 the system of downs was introduced to thwart Princeton's and Yale's strategy of controlling the ball without trying to score. In 1883 the number of players was reduced, at Camp's urging, to eleven, and Camp introduced the soon standard arrangement of a seven-man offensive line with a quarterback, two halfbacks, and a fullback.

On September 3, 1895 the first professional football game was played, in Latrobe, Pennsylvania, between the Latrobe YMCA and the Jeannette Athletic Club. (Latrobe won the contest 12-0.).

By the 1890s interlocking offensive formations such as the flying wedge and the practice of teammates physically dragging ball-carrying players forward had made the game extremely dangerous. Despite restrictions on the flying wedge and other precautions, in 1905 eighteen players were killed in games. President Theodore Roosevelt informed the universities that the game must be made safer. To force them to respond to his concerns, he threatened to pressure Congress to make playing football a federal crime.

In 1906, two rival organizing bodies, the Intercollegiate Rules Committee and the Intercollegiate Athletic Association, met in New York; eventually they agreed on several new rules intended to make the game safer, among them the addition of a neutral zone between the scrimmage lines and a requirement that at least six players from each team line up on them. The most far-reaching innovation they considered, though, was the legalization of the forward pass. This was very controversial at the time, much derided by purists. As an alternative means of opening out the play, Walter Camp would have preferred widening the field; but representatives from Harvard pointed to recently constructed Harvard Stadium, which could not be widened, and the forward pass was adopted; it has come to shape the whole history of American football, as opposed to its cousins around the world.

In 1910, after further deaths, interlocking formations were finally outlawed; and in 1912 the field was changed to its current size, the value of a touchdown increased to 6 points, and a fourth down added to each possession. The game had achieved its modern form.

Problems in football

Main article: Issues in American Football

Injuries are more common in American football than in many other sports, although rule changes made in the past 90 years (for instance, the elimination of "horse-collar tackles") have gradually lowered the rates of injuries. In addition, protective equipment has become better - for example, the optional leather helmets introduced during the 1890s have been replaced (in several stages) by required high-tech padded plastic helmets with bars protecting the face.

More recently, the use of steroids and the extent thereof has become an object of debate in professional, college, and even high school football leagues. (Pop Warner leagues so far appear to be immune to questions of whether players "juice up" or not.)

Another problem with football is that it is an expensive sport. The specialized helmets, uniforms, and pads can cost hundreds of dollars. There is a widespread perception that football teams based in schools and public recreational leagues consume far more than their fair share of the sports budget, although sales of tickets to college (and to some extent high school) football games often make it a revenue-producing sport.

Professional, college, and other leagues

Football is played at a number of levels in the United States and abroad. These include the following:

• The National Football League (NFL) - top-level men's professional league
• College football - played by many US colleges
• The Arena Football League - mid-level men's professional league. Played in indoor stadiums, hence the name "arena" football. One of the nation's fastest-growing sports.
• The Canadian Football League (CFL) - men's professional league based in Canada, played using a slightly different set of rules known as Canadian football
• The Mexican College Football League or ONEFA - played by many Mexican colleges, with essentially NCAA rules
• The North American Football League - Amateur minor league with more than 100 member organizations since 1996,
• Women's American football - since 2000, there has been a surge of women's professional leagues.
• High school football - played by most high schools
• Nine-man football, Eight-man football, and Six-man football - variations of high school football, usually played in sparsely populated areas
• Amateur and youth league football
• Flag football and Touch football - non-tackle; almost exclusively amateur
• Pop Warner or youth football - involves younger children who are too young to play high school, generally in middle school.
• Sprint football - players must weigh no more than 172 pounds
• British Collegiate American Football League (BCAFL) - Fast-growing college football league in the UK

The descriptions in this article are based primarily on the current rules of the National Football League (NFL, 1920-present). Differences with college rules will be noted. Professional, college, high school, and amateur rules are similar.

Professional leagues that no longer exist include the World Football League (WFL, 1974-75), the United States Football League (USFL, 1983-1985), the XFL (XFL, 2001), the All-America Football Conference (1946-1949) (2 teams are now in the NFL), the World League of American Football (WLAF, 1991-1993 — now NFL Europe), and four separate American Football Leagues (AFL, 1926, 1937-28, 1940-1941 and 1960-1969). The fourth AFL (1960-1969) merged with the NFL in 1970 and now exists (mostly) as the AFC with several new teams. The old NFL appeared as the NFC.

References

• Digest of Rules. National Football League. URL accessed on January 15, 2005.
• History and the basics. National Football League. URL accessed on January 15, 2005.
• Playing with the Percentages When Trailing by Two Touchdowns. Montana State University. URL accessed on December 24, 2005.

See also

• American football strategy
• National Women's Football Association
• Canadian Football League
• German Football League
• American football glossary
• List of American football players
• Pro Football Hall of Fame
• List of defunct sports leagues
• Fantasy Football
• Gridiron football

External links

• The National Football League (NFL) - the top professional league
• NFL Players Association
• NCAA Playing Rules (complete college football rules are available as a PDF file)
• American Football Coaches Association
• Movie of 1903 football game between the University of Chicago and the University of Michigan
• Chronology of many events in the NFL
• The Women's League

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