Misplaced Pages

This is an old revision of this page, as edited by Karmafist (talk | contribs) at 07:58, 17 December 2004 (→Naming). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

American football, known in the United States simply as football, is a competitive team sport that rewards players' speed, agility, skill, tactics, and brute strength as they run and throw a ball, and block, tackle, and outrun each other, trying to force the ball further into their opponent's territory and ultimately into the endzone.

It is one of the more physically demanding sports, with a great deal of physical contact occurring on every play as players often weighing 300 pounds (~135 kg) or more shove each other with all of their strength, and with a clearly defined front line, moving up and down the field, separating the offensive and defensive squads.

American football does not much resemble soccer, the sport which most people outside the U.S. call "football". Consequently, American Football is best known internationally as "American Football". However, both of these games 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, usually known simply as "Rugby". According to an apocryphal story rugby football began with a football game at Rugby School in England in 1823 when a player named William Webb Ellis suddenly ran with the ball only to be tackled by an opponent. Contrary to popular belief the game played at Rugby School was not soccer (which had yet to be codified) and the Rugby School version of football had always permitted handling the ball but had banned running with the ball. This rule breaking gradually became increasingly common until it became the accepted norm. Thus was born the game of Rugby Football.

The game progressed from that point and was introduced to North America from Canada, by the British Army garrison in Montreal, which played a series of games with McGill University. In 1874, McGill arranged to play a few games in the United States, at Harvard, which liked the new game so much that it became a feature of the Ivy League. Both Canadian and American football evolved from this point. The U.S. game still has some things in common with the two varieties of rugby, especially rugby league.

For an in-depth overview of the differences and similarities of Canadian football and American football see: Comparison of Canadian and American football

Popularity

Since the 1990s, football has surpassed even baseball as the most popular spectator sport in the US. The 32-team National Football League (NFL) is the most popular professional 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. In additions, some players are voted the honor to play in an All-Star game, the Pro Bowl, in Honolulu.

College football is extremely popular, with many major colleges and universities playing NCAA (National Collegiate Athletic Association) Division I football, and consistently selling out huge stadiums. College games are widely televised and widely watched. Many institutions in lower NCAA divisions and the National Association of Intercollegiate Athletics (NAIA) also field varsity football teams, as do most high schools. High school football is popular in many parts of the US, notably Texas, with games sometimes attracting tens of thousands of fans.

In addition, football is played on amateur, club and youth teams (such as teams in the Pop Warner leagues). There is an American Football World Cup. In addition, there are many "semi-pro" teams, meaning the players are paid to play, but at a small enough salary that they generally must also have a full-time, more traditional job.

Naming

The word football has a number of different meanings. In the United States football almost always means what, in the rest of the English-speaking world, is usually called American football (or in some cases Gridiron football). In most of the rest of the world, the word football means the game that is called soccer in the US, although it is occasionally called Association football or International football. Soccer, the most popular form of football world-wide, is also somewhat popular in the US, particularly as a participation sport for children. It is played at all levels, youth, amateur, high school, college and professional, and in internationals by teams involving both sexes (see: football (soccer))

The name football might seem a curious name for the sport of American football, as the players' feet rarely have much to do with the ball -- kicking the football is only allowed in certain situations and is most often inadvisable or would result in a penalty. The vast majority of game time involves players holding the ball in their hands as they run. However, the sport is a direct descendant of rugby union football (which in turn descended from soccer), as explained below, and has retained the name.

In fact the word soccer is of British origin, being a corruption of 'Association' the governing body of English soccer being the Football Association. Football is also occasionally used by followers of the sports of Rugby Union, Rugby League, Gaelic Football and Australian Rules Football to refer to their sport. Like Americans they refer to Association Football as 'soccer'.

In the remainder of this article, the word football refers to American football.

Professional, college, and other leagues

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

• Professional football (NFL)
• Women's football
• Arena football - (professional) played indoors
• College football - played by many US colleges (very popular)
• High School football - played by most high schools
• Eight-man football - an eight-player variation of high school football, usually played in sparsely populated areas
• Six-man football - a six-player variation of high school football
• Amateur and youth league football
• Flag football - non-tackle; almost exclusively amateur
• Touch football - also non-tackle and almost exclusively amateur
• Pop warner or youth football- Involves younger kids that are too young to play high school, generally in Middle school.

The descriptions on this page 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. The minor Arena Football League (1987-present) plays an indoor adaptation of American football, at a faster pace, on a smaller field with no built-in sidelines -- the edges of the grid are coincident with padded walls similar to those found in a baseball outfield. Flag football and touch football are non-tackle versions of American football.

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), the World League of American Football (WLAF,1991-1993-now NFL Europe), and, the American Football League (AFL,1960-1969). Since 2000, there has been a surge of women's professional leagues.

The game

Gameplay in American football consists of a series of individual plays of short duration, outside of which the ball is not in play. Substitutions can be made between plays, which allows for a great deal of specialization as coaches put in players they think are best suited for any particular situation. The game is very tactical and strategic. With 22 players on the field at a time (eleven on each team), each with an assigned task for a given play, complex strategies have arisen for every part of the game.

Object of the game

The object of the game is to advance the ball to the opponent's endzone and thus score points. The team with the most points when time has expired wins.

Duration, kickoffs and free kicks

Collegiate and professional football games are 60 minutes long, divided into two halves separated by a halftime. Each half consists of two quarters, each 15 minutes long. In high school, 12 minute quarters are usually played, resulting in a 48-minute game. Teams change ends of the field after the first and third quarters. If a game is tied at the end of regulation, overtime is played. Professional overtime periods are "sudden death", meaning that the teams that scores first, by any means, wins. In college football, an overtime procedure ensures that each team has equal opportunity to score.

A free kick is a special play which does not occur from scrimmage. The kicking team begins behind the ball, while the receiving team must remain at least 10 yards downfield before the ball is kicked.

A kickoff is a kind of free kick used to start each half, and also used to restart the game following a field goal or touchdown. The kicking team kicks off from its own 30-yard line, though that can be affected by any penalties on the preceding play. (Note: the ball is usually kicked from the 35-yard line in college football). The ball must be kicked from the ground, not punted. A tee is used, unless the ball is blown off the tee by winds twice in succession, in which case the ball must be held by a member of the kicking team. The receiving team may recover and attempt to advance the ball at any time after the kick, but the kicking team may not field the ball until it has traveled at least 10 yards. The ball is usually just kicked deep to the receiving team, but sometimes a team will attempt to recover its own kick, in a play known as an onside kick. If a kickoff goes out of bounds in the end zone, or if it is downed in the end zone, it is ruled a touchback and the ball is spotted on the receiving team's 20-yard line. If a kickoff goes out of bounds before being touched by a player for the receiving team, it is a penalty on the kicking team. The ball is spotted at the point where it went out of bounds, or 30 yards from the point of the kick, whichever is closer, and the receiving team takes possession.

A free kick is used to restart the game following a safety, which is the (infrequent) event occurring when the team with possession of the ball is downed in its own endzone. The team that was trapped in its own endzone, therefore conceding two points to the other team, kicks the ball from its own 20-yard line. In this case, the free kick may be either punted or kicked from the ground, but a tee may not be used and the ball may not be held on the ground.

In the NFL, under an infrequently-used rule, a free kick may be taken on the play immediately made after any fair catch as a field goal attempt. The ball must be held on the ground by a member of the kicking team; a tee may not be used. If the ball goes between the goal posts, a field goal is scored for the kicking team. This is the only case where a free kick may score a field goal.

Methods of scoring

Points can be scored in the following ways.

• A field goal, worth 3 points, is scored by snapping or hiking the ball to a place holder where he holds up the ball and the kicker kicks the ball between the uprights of the goal posts. (If a field goal is missed, the ball is returned to the original line of scrimmage , and possession is given to the other team. Optionally, the other team may catch the kicked ball and attempt to advance it, but this is usually not advantageous.)
• A touchdown, worth 6 points, is achieved when a player has legal possession of the ball within the opponent's end zone. Scoring a touchdown is the ultimate goal of the offensive team. A touchdown can also be scored by the defense by an interception or fumble recovery when the ball is taken to the opponent's endzone.
• One or two extra points may be scored following a touchdown. The team which scored the touchdown is given a conversion attempt (also called a "try"). The ball is spotted at the 2 yard line (NFL) or 3 yard line (college), and the team which scored the touchdown is allowed to run a single play in which they may score either one or two additional points. In the NFL, if a defender gains possession of the ball, the try is immediately over. The defending team can only score during a conversion attempt by the other team in college football, where if a defender gets possession of the ball and carries it into the opposing end zone, his team gets two points. This rule was adopted by the NCAA in 1990, but is not used anywhere else.
  • An extra point, worth 1 point, is scored in the same way as a field goal is scored during regular play.
  • A two-point conversion is scored in the same way as a touchdown is scored during regular play.
  • One point is awarded for a safety (see below). In college football, this can occur when the defense gains control of the ball, then fumbles it out of bounds in its own end zone. In the NFL, since the try ends once the defense gains possession, a safety can only be scored if a defensive player bats a loose (fumbled) ball out of bounds in the end zone.
• A safety is an infrequently-occuring score worth 2 points (except when it occurs on an extra-point attempt, when it is worth 1 point, as noted above). It occurs when a player causes the ball to become dead in his own end zone. The points are awarded to the opposing team. This can happen if a player is either downed or goes out of bounds in the end zone while carrying the ball, or if he fumbles the ball, and it goes out of bounds in the end zone. A safety is also awarded to the defensive team if the offensive team commits a penalty within its own end zone. Also, a defensive score during a conversion attempt in college football (see above) is officially recorded as a safety. However, if a player intercepts a pass or receives a kick in his own end zone and is downed there, it is a touchback, not a safety, since the player did not cause the ball to enter the end zone. If the interception or reception occurs outside the end zone, and the player is carried into the end zone by momentum, the ball is placed at the spot of the catch and no safety is awarded. While the 2 points awarded for a safety may make it seem as if it is not worth very much, an additional advantage is gained in that the scoring team retains possession of the ball. Furthermore, since the kick following a safety is a punt from the 20 yard line, rather than a place kick from the 40 yard line, it usually results in good field position for the scoring team. In other words, the team scoring a safety is put in a position of controlling the game and having a better-than-usual chance of scoring on their subsequent offensive drive.

The field

The field is a rectangle 120 yards (ca. 110 m) long and 53 1/3 yards (50 m) wide, defined by sidelines running the length of the field and endlines running the width. There is a goal line ten yards in from each end line and parallel to it. The two goal lines are thus 100 yards (90 m) apart. The area of the field between the goal lines is called the field of play. At each end of the field, the end zone is the area between the goal line and the end line.

Within the field of play, additional markings include yard markers, as well as inbound lines (also called hash marks), every yard the length of the field. The inbound lines (hash marks), which are short lines perpendicular to the yard markers, differ in distance from the sidelines at each main level of the game:

• NFL: 70¾ feet (21½ m) from the sidelines; this means that the hash marks are separated from one another by the width of the goalposts.
• College: 60 feet (18¼ m) from the sidelines.
• High school: 53 1/3 feet (16¼ m) from the sidelines, dividing the field into thirds.

Every 5 yards (4.5 m), the yard markers run the width of the field, and every 10 yards, they are marked by numbers indicating the distance, in yards, from the nearest goal line.

At the center of each end line is a set of goal posts, which have two upright posts extending above a crossbar. The distance between upright posts is 18½ feet in general and 23 1/3 feet in high schools (5½ m, 7 m), and the top of the crossbar is 10 feet (3 m) above the ground.

Play of the game

A game consists of many individual plays. The vast majority of these are scrimmage plays. Each play from scrimmage is one of a series of downs given to the team with possession. These two concepts, the concept of scrimmage, and the concept of downs, are fundamental to American football, and are what distinguish it, as well as Canadian football, from most other forms of football. However, rugby league does have a similar system where each side is allowed to be tackled six times while in possession before surrendering possession (see the entry for rugby league for an explanation of the play-the-ball and the limited tackles rule).

A set of downs begins with a first down, which is given to a team either after it has just gained possession on the previous play, or it has gained the necessary yardage from a previous set of downs. On a first down, the team with possession is given four downs to gain 10 yards (they have "a first and ten", meaning that it is first down, and they need ten yards to get another first down). The line a team must reach in order to gain a first down is technically called the line to gain, although it is commonly called first down yardage. The team with possession is called the offensive team, and the other team the defensive team.

Plays from scrimmage

Each down is a play from scrimmage. Prior to each play from scrimmage, the two teams line up on opposite sides of a line of scrimmage, which is defined by the spot of the ball from the previous play. The spot is, in most cases, the yard line at which the ball became dead on the previous play, plus or minus any penalty yardage. A down, or play from scrimmage, begins with a snap and ends when the ball becomes dead for any reason. A snap is either a handoff between the legs from the center to the quarterback, or it is a pass between the legs from the center to the quarterback, or possibly to a player other than the quarterback, such as a punter or a holder for a field goal attempt. The ball may become dead, ending the down, because a player in possession is tackled, or because his forward progress is stopped, or because he goes out of bounds, or because a forward pass goes incomplete.

Advancing the ball

There are two methods that can be used to advance the ball while still maintaining possession:

• Running with the ball - The quarterback, who is the player that normally has the ball following the snap, may run the ball but, more often, he either hands the ball, or throws a lateral pass to a running back, who then becomes the ball carrier. Most other players on the offense have blocking assignments.

• A forward pass - A forward pass may only be thrown on a play from scrimmage, and only from behind the line of scrimmage. It must be thrown to an eligible receiver (any player who is not an interior lineman). A completed pass is one caught by an eligible receiver. The player may run with the ball after catching it. To be considered "in bounds" a receiver must have clear possession of the ball and place both feet (NFL) or one foot (college) in bounds prior to stepping out of bounds. An incomplete pass is any forward pass that either hits the ground or goes out of bounds, at which point the ball becomes dead, and is spotted at the preceding line of scrimmage for the following play. An interception is a pass caught by the defense, which transfers possession to the defending team, which may then run with the ball.

It is important for the offense to run a variety of running and passing plays in order to keep the defense uncertain of the next play. If the quarterback has two broken fingers on his throwing hand, for example, the defense can safely risk lining up in a run defense for nearly every play, which should successfully squelch the offense's running backs.

Fourth down situations

If a team uses all four of its downs without gaining the yardage for a first down or a touchdown, possession goes to the other team. Fourth down situations are therefore pivotal. The offense has three choices: "go for it", punt, or attempt a field goal.

Things the offense may decide to do on fourth down:

• "go for it" - despite the risk involved, a team may always elect to "go for it" on fourth down by making one last all-out attempt to reach the first down marker, mounting a regular running or passing play to get there (just as they did on the first three downs). This is most common when, thanks to a team's success on the first three downs, the distance required for a first down is short; or when it is trailing late in the game by more than three points (the value of a field goal). The risk is significant: failing to make the next first down gives the ball to the opposing team with what is probably much better field position than a kick would leave them with. The safe thing to do is usually to kick the ball.
• punt - A team will punt in order to gain better field position.
• attempt a field goal - Field goal attempts must be made with the ball on the ground (they cannot be punted), so a player called a holder holds the ball for a kicker. (In times past, a kicker might have tried a "drop kick" -- that is, dropping the ball and kicking it after it bounces off the ground -- and if the kicker kicks it through the goalposts, it is a field goal. This is difficult to do, as the ball is in the shape of a prolate spheroid and its bounce is unpredictable. Nowadays, the only time you will see this is by a hurried kicker after a broken play.) Failed field goal attempts, if they are short, can be returned by the opponent, but the ball usually goes past the end line and can't be returned. If the field goal attempt fails, the ball is spotted at the original line of scrimmage or the 20-yard line of the non-kicking team, whichever is farther from the goal line, and possession is given to the other team. (In the NFL, failed field goal attempts are spotted at the spot of the kick or the 20, whichever is farther from the goal line.) Field goals can also be attempted on other downs, but this is only seen in situations where a field goal will either win or tie the game and the distance to kick the field goal is well within range of the kicker.

A team will occasionally run a trick play on fourth down. They will line up as if to punt or attempt a field goal, but will instead run the ball or pass it in an attempt to pick up a first down.

Specialized units and players

With its unlimited substitutions, American football is highly specialized, with most teams having three specialized units: an offensive unit, a defensive unit, and special teams. There are many specialized players within each unit. Some players may only be used in certain situations. (for details see: offensive unit, defensive unit, special teams, linemen.)

A list of player types and definitions can also be found in the Glossary of American football.

Penalties

Some of the more common penalties are listed below. In most cases the offending team will be assessed a penalty of 5, 10 or 15 yards, depending on the infraction. There may also be a loss of down for an offensive penalty against the defense. Conversely, a defensive penalty against the offense may result in an automatic first down. In some cases, the offense will be given the option of declining the penalty and taking the yardage gained on the play. For some infractions by the defense, the penalty is applied in addition to the yardage gained on the play. Most of a number of personal fouls, which involve danger to another player, carry 15-yard penalties; in rare cases, they result in specific players being ejected from the game.

With three exceptions, no penalty may move the ball more than half the distance toward the penalized team's goal line. These exceptions are defensive pass interference (see the discussion of that penalty for more details), intentional grounding, and offensive holding - but in this last case the exception pertains only if the infraction occurs within the offensive team's own end zone, in which case an automatic safety is assessed (intentional grounding from the end zone also carries an automatic safety).

Note: The neutral zone is the space defined by lines drawn through the ends of the ball parallel to the yard lines when the ball is spotted and ready for play. No player may legally have any part of his body in the neutral zone when the ball is snapped, with the exception of the center.

Penalties against the offense

• False start (5 yards) - any player moving after they have gotten in their set position before the snap in a way that simulates the start of the play (on occasion this is informally referred to as "traveling," because the signal the official makes to identify the penalty is almost exactly the same as the one a basketball referee makes when calling the infraction of traveling, or "walking" with the ball, in that sport)
• Illegal motion (5 yards) - having more than one back in motion at the snap, or a man in motion moving forward at the time of the snap
• Illegal shift (5 yards) - not being set before the snap
• Illegal formation (5 yards) - having fewer than 7 players on the line of scrimmage
• Delay of game (5 yards) - allowing the 40 seconds given to elapse before the snap (this is sometimes intentionally done on a play where the offense is about to punt from relatively advanced field position - and often the defensive team declines the penalty)
• Ineligible receiver downfield (5 yards) - a lineman beyond the neutral zone prior to a forward pass
  • This penalty is not imposed if the receiver is behind the line of scrimmage when he receives the pass. This exception has been added to accommodate the screen pass, where a receiver (most often a back, but sometimes a tight end or wide receiver) catches a ball behind the line of scrimmage behind a "screen" of offensive linemen.
• Illegal forward pass (5 yards and loss of down) - thrown from beyond the neutral zone, or a second forward pass on the same play (originally, intentional grounding - see below - was considered a subset of this; they are now treated as separate infractions)
• Holding (10 yards) - illegal use of the hands or arms while blocking; an automatic safety is assessed instead if spot of infraction is within the offensive team's own end zone.
• Offensive pass interference (10 yards) - interfering with a defender attempting to catch a pass
• Intentional grounding - throwing the ball into the ground to avoid being tackled
  • NFL penalty: 10 yards or spot of foul, whichever is farther from the original line of scrimmage, and loss of down
  • College penalty: Spot of foul and loss of down
  • In both NFL and college, intentional grounding from the offensive team's own end zone constitutes an automatic safety unless the defense chooses to decline the penalty, which might only ever happen if the infraction had occurred on a fourth-down play.
    • Note that at any level, if the quarterback has moved outside the area between his offensive tackles, there is no penalty for grounding the ball if the quarterback throws the ball past the line of scrimmage. Also, "spiking" the ball into the ground to stop the clock is always legal, as long as the quarterback's primary intention is to stop the clock (or, far less commonly, to prevent the opposing team from making an instant replay challenge concerning the result of the immediately previous play, as no such challenge can be recognized once another play has been run).
• Illegal block in the back (10 yards) - an illegal block from behind and above the waist
• Clipping (15 yards) - an illegal block from behind and below the waist
• Illegal block (15 yards) - usually a "crackback block".

Penalties against the defense

• Offsides (5 yards) - Being across the line of scrimmage before the ball is snapped, or being in the neutral zone when the ball is snapped; unlike offensive players, defensive players are not compelled to come to a set position before the snap, so if a defender jumps across the line but gets back to his side before the snap there is no penalty. The offense can decline the penalty and take the yardage gained on the play - unlike in the case of a false start penalty against the offense, whereupon the play will be immediately aborted by the officials.
• Encroachment (5 yards) - A defensive "false start," often before the ball is snapped (sometimes regarded as a subset of "offsides" above; indeed, the same referee's signal is used to denote both of these penalties)
• Running into the kicker (5 yards) - during a kick from scrimmage
• Pass interference
  • NFL: An automatic first down and the ball is moved forward to the location of the interference -- a devastating penalty if the play was a long pass. If the interference takes place in the end zone, the ball is placed on the one-yard line.
  • College: An automatic first down. Penalty is 15 yards or the spot of the foul, whichever is closer to the previous line of scrimmage. The half-the-distance rule does not apply, unless the previous line of scrimmage was on or inside the 2-yard line. If the ball was snapped between the defensive team's 17-yard and 2-yard lines, and the foul occurred inside the 2-yard line or in the end zone, the ball is placed on the 2-yard line.
  • High school: 15 yards and an automatic first down; the half-the-distance rule always applies.

At any level, if the receiver is interfered with behind the line of scrimmage, the defender cannot be charged with pass interference (although he may be guilty of a different penalty). This nuance in the rules almost never arises, but can conceivably occur on a screen pass. Pass interference is also rendered inapplicable if the ball was tipped by a player on either team prior to the contact being made, regardless of how slight or incidental the "tipping" was.

• Defensive holding or Illegal use of hands (5 yards and an automatic first down) - illegal use of the hands or arms either while attempting to ward off a block, or to cover a receiver (separate referee's signals are used in these instances; if the infraction involved the defender illegally placing his hands on any part of the fouled player's face, the official will accompany the signal with the words "hands to the face")
• Illegal contact (informally, "illegal chuck," 5 yards and an automatic first down) - any contact made between a defender and a receiver after the latter has traversed more than five yards beyond the line of scrimmage; this rule was adopted in 1978, and its enactment is regarded as contributing to the dramatic increase in both passing yardage and scoring the NFL has witnessed since that time.
• Piling on (15 yards and automatic first down)
• Roughing the kicker (15 yards and automatic first down) - tackling the kicker after he has kicked the ball
• Roughing the passer (15 yards and automatic first down) - tackling the quarterback after he has thrown a forward pass

Penalties against either team

• Too many players on the field (5 yards)
• Grabbing the face mask (5 or 15 yards) - If there is pulling, twisting or turning, 15 yards; if not, and if the foul is committed by the defensive team, 5 yards. In the NFL, any face mask penalty on the defense results in an automatic first down; in college, only the 15-yard face mask results in an automatic first down. Intent is not a factor. Just touching an opponent's face mask, without grabbing it, is not illegal. In rare cases where an offensive player - particularly a lineman - commits this foul and pulling or twisting is not involved, holding will generally be called instead. This penalty is also occasionally called against a ball carrier who, attempting to "stiff-arm" a pursuing defender, inadvertently touches the latter's face mask; when this occurs a 5-yard penalty is usually assessed.
• Unsportsmanlike conduct (15 yards) - Any conduct by anyone involved in the game—usually a player, but occasionally a coach, and very rarely one or more spectators—deemed to be especially objectionable by the game officials, or by rule. Examples include throwing punches, deliberate physical contact with officials, verbal abuse of officials, and taunting, which, since 2004 in the NFL, has included any "prolonged and premeditated celebrations" by players (prior to that year these latter carried only a 5-yard penalty).
• Sideline Violation (5 yards) - Called if a coach or player on the sidelines is on the edge of the field during the snap. An official will usually issue a "Sideline Warning" once before issuing a penalty.
• Palpably unfair act (touchdown) - A situation in which a player or other person not legally in the game at the start of a given play comes onto the field, such as someone coming off the bench to tackle a player apparently en route to a touchdown. This can also conceivably be invoked in cases where the defense commits repeated intentional infractions very close to its own goal line (the half-the-distance rule making the consequence of such infractions otherwise infinitesimal).

Development of the game

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.

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.

Football strategy

Offensive strategy

General:

• Clock management
• Grind it out
• Hurry-up Offense / Two-minute Drill
• Mixing up the play calling
• No-huddle offense
• Option offense
• Passer rating
• Red zone
• Run & shoot
• Scripted plays
• Sending a man in motion
• Trick plays
• Use of snap count to draw offsides
• West-coast offense

Formations:

• Double tight end
• Empty backfield
• I-back formation
• Shotgun
• Wishbone and T formations

Run:

• Quarterback bootleg
• Quarterback sneak
• Reverse, double reverse
• Draw play
• Straight up the middle
• Student body right
• Trap block

Passes:

• Down-and-in, Down-and-out patterns
• Flea-flicker pass
• Going through the rotation
• Hail Mary pass
• Halfback pass
• Holding blocks
• Lob pass
• Outlet pass
• Play-action pass
• Post pattern
• Pump fake
• Running interference
• Screen
• Shovel pass
• Slant pattern
• Statue of Liberty play
• Tackle eligible
• Throw a bomb downfield / Fly pattern
• Using the sideline

Defensive strategy

The general goal of defensive strategy is to prevent the offensive opponent from scoring, and to either gain control for their offense or to score themselves. There are many different defensive strategies.

3-4

The 3-4 defense has declined in popularity over the years, but it is still used by some professional football teams and by a few college football teams. The 3-4 defense is so named because it involves 3 down linemen and 4 linebackers. There are usually 4 defensive backs.

The 3 down linemen attempt to break into the backfield in order to sack or rush the quarterback or to stop running backs and other players behind the line of scrimmage. The defensive line is made up of a nose tackle (NT), who lines up in front of the opposing team's center and two defensive ends (DEs), who flank the nose tackle on both sides.

4 linebackers line up behind the defensive line. In a 3-4 defense, the linebacker unit is made up of two middle or inside linebackers (MLBs/ILBs), who are flanked on both sides by outside linebackers (OLBs). Linebackers often try to break into the offense's backfield or they stay back to defend against the pass or the run.

4-3

The 4-3 defense is probably the most commonly used defense in modern American Football. The 4-3 defense is so named because it involves 4 down linemen and 3 linebackers. There are usually also 4 defensive backs.

The 4 down linemen attempt to break into the backfield in order to sack or rush the quarterback or to stop running backs and other players behind the line of scrimmage. The defensive line is made up of two defensive tackles (DTs) and two defensive ends (DEs). The two defensive tackles line up in the middle of the line, in front of the opposing team's center. The two defensive ends flank the defensive tackles.

3 linebackers line up behind the defensive line. In a 4-3 defense, the linebacker unit is made up of a middle or inside linebacker (MLB/ILB), who is flanked on both sides by outside linebackers (OLBs). Linebackers often try to break into the offense's backfield or they stay back to defend against the pass or the run.

Nickel

The nickel defense is employed in obvious passing situations, or against a team that frequently uses four-wide receiver sets on offense. The defense has 5 defensive backs, and has either 4 down linemen and 2 linebackers or 3 down linemen and 3 linebackers.

In most defenses, the secondary consists of two cornerbacks (CBs), a free safety (FS) and a strong safety (SS). The nickel defense adds an extra defensive back, known as the "nickel back" (NB), in order to defend against the pass. A nickel back is also employed in the "dime" defense (see below) and are usually free or strong safeties, although cornerbacks can be utilized as well. The term "nickel" comes from the five-cent value of a United States nickel.

Dime

The dime defense is usually employed in obvious passing situations. The formation usually consists of 6 defensive backs, and has either 4 down linemen and 1 linebacker, or 3 down linemen and 2 linebackers.

A dime defense differs from the nickel in that it adds yet another defensive back to the secondary. The sixth defensive back is called a "dime back" (DB). The defense gets its name because a dime is higher in value than a nickel.

Quarter

The Quarter defense has 3 down lineman, one linebacker, and 7 defensive backs. This is usually only used in a third-and-very long situation, or when the opposing team is definitely going to pass. This gets its name because a quarter is higher in value than a nickel or a dime.

Cover 2

The Cover 2 defense, also known as a "1-gap" defense, is a variation of the 4-3 defense. Each player on defense is responsible for defending the 'gap' between the two opposing offensive players. The success or failure of the Cover 2 defensive implementation relies solely on each individual defender successfully defending their assigned gap. Defensive players must each defend their gap and, in the case of the linebackers and secondary, are also responsible for a certain 'zone' (area on the field of play) in the secondary.

The Cover 2 defense utilizes 4 down linemen for rushing the passer, 3 linebackers responsible for run and pass defense, and a secondary consisting of 2 cornerbacks, a strong safety, and a free safety. Although the secondary's primary responsibility is pass defense, it too is involved in stopping the run. Particularly the strong safety, which will, in potential running situations, line up near the linebackers, in effect, taking the role of an additional linebacker. This is known as 'putting 8 men in the box' to stop the run.

The Cover 2 defense is designed to counter the West Coast offense philosophy of using high percentage passes to maintain ball control. The West Coast offense is designed for getting yards after a catch has been made. The Cover 2 defense is designed to eliminate the run after the catch. The Cover 2 is meant to place maximum pressure on the quarterback via the 4 down linemen. The strategy behind this tactic is that if the quarterback is successfully pressured in this way, the quarterback will not be able to get into a rhythm offensively, hence he will make more mistakes: interceptions, incompletions, fumbles, etc. Any defensive player can blitz the quarterback during the course of the game, adding to the quarterback's confusion. Often, instead of a straight out blitz, a corresponding defensive lineman might drop back into short pass coverage to make up for the blitzing linebacker/defensive back. This is known as a 'zone blitz'. In addition, once the blitz is successful, the defense can later 'show' a blitz before the snap, causing the quarterback to call an audible at the line of scrimmage, and then fake the blitz. But the blitz in the Cover 2 defensive scheme is utilized as a strategy of choice rather than a necessity of play.

One of the strengths of the Cover 2 defense is its ability to mask what the defensive players will do after the snap of the ball, since each down, the players line up in exactly the same formation. There are nickel and dime versions of the Cover 2 as well, in which a nickel/dime back is substituted appropriately for a linebacker in more pass-oriented downs.

The weakness of the Cover 2 defense is that the cornerbacks are relied on heavily in both run and pass defense. A defensive breakdown or missed tackle at the conerback position can oftentimes result in a big gain for the opposing offense. The Cover 2 defense is built on the premise that 'speed kills', hence, players in a Cover 2 defense are usually smaller and faster than their counterparts in a traditional 4-3 defense. This lack of size and mass is usually compensated by the fact that often, an offensive player with the ball is being tackled by two, three, or sometimes even more defensive players on any given play.

The premier example of the Cover 2 defense is the 2002 Superbowl XXXVII Champion Tampa Bay Buccaneers. In Superbowl XXXVII, Tampa Bay, ranked the #1 defense in the league, defeated the #1 ranked offense in the league, the Oakland Raiders, 48-21. Oakland quarterback Rich Gannon was sacked 5 times, threw 5 interceptions (3 interceptions were returned for touchdowns), and for the most part, was ineffective against the Cover 2 defense of the Buccaneers. Oakland was equally ineffective running the ball against Tampa Bay as well.

Eight in the box

The defensive linemen and linebackers collectively are often referred to as "the box" and thus normally number seven players; on occasion, however, circumstances call for an additional man to be placed therein (generally a linebacker if the team uses the 4-3 as its base alignment, or a defensive lineman in cases where the 3-4 is ordinarily utilized), whereupon one player in the secondary (most commonly the free safety) is removed from the lineup. Sometimes a player in the secondary (usually the strong safety) acts as an additional linebacker. Some teams use a defensive system in which one of the players is cross between a linebacker and a free safety called a "rover".

Teams most often put "eight in the box" or "pack the box" when the opposing team has a weak passing game and relies heavily on the running attack. By having more players in "the box", the defense can more effectively contain the opposing team's running game. In so doing, the defense "dares" the other team to throw the football.

Special teams strategy

General topics:

• Field position
• Touchbacks

Kicking team topics:

• Downing the ball inside the 20
• Fake punts
• Kick-offs out-of-bounds
• Onside kicks
• Preventing a run-back / "Bloopers" on kick-off
• Punts out-of-bounds

Receiving team topics:

• Blocking punts
• Deciding whether to "take it out"
• Fair catch
• Roughing the kicker

Beyond recreation and entertainment

Football and drugs

Contemporary football players are larger than their predecessors of only 30 or 40 years ago. It is quite normal, for instance, for all the members of the offensive line of a major college or professional team to weigh more than 300 pounds (136 kg.), whereas in the 1960's linemen who weighed only 270 pounds were common. The increase in player size has led to an increase in the frequency and severity of injuries.

Since nutritional standards and weight-training technique were already quite advanced even in the 1960's, it has been conjectured that much of the increase in the size of the players is the result of the widespread availability of illegal anabolic steroids, which facilitate increased growth of muscle tissue. Such drugs are widely available even to high school players.

Because anabolic steroids have dangerous side effects, the National Football League tests its players for steroids, and penalizes those who are caught. However, it has recently emerged that new varieties of steroids are being developed in clandestine laboratories, which elude existing drug tests. Hence there is a kind of "arms race" between the scientists who develop new kinds of illegal steroids and those who develop tests to detect them.

Injuries

Despite the helmets and heavy padding worn by all players on the field, injuries are common in football. An "Injury Report" section is ubiquitous in American newspapers' sports sections, detailing, for each injured player on each team, his injury and the amount of time he is expected to be out. Twice-weekly during the season (Wednesdays and Fridays), all NFL teams must report the status of their injured players, or be subject to a fine from the league. The standard severity descriptions are "out" (will not play in the coming game); "doubtful" (25% chance of playing); "questionable" (50% chance of playing); or "probable" (75% chance of playing). Note that teams occasionally manipulate their injury reports, minimizing or maximizing the extent of a player's injury, as an attempt to strategically deny their upcoming opponents a clear picture of the team's health. Similar systems are in place for most major American sports.

The NFL has a roster limit of 53 players per team during the season; 45 of which dress for a game plus an "emergency quarterback" who only plays if all the quarterbacks on the 45-man roster are out of the game. Players who are injured are frequently among the eight that do not dress. If it becomes certain that a player will not play for the rest of the season, the team may put him on the "Injured Reserve" list and replace the player on the roster.

An average of about eight players die each year in the United States as a result of injuries received in games at all levels. About 160 concussions occur every season, and the National Football League now collects benchmark measures of awareness for each player, which can be used during a game to judge whether he has been concussed.

Injuries sustained by football players often are permanent. Many former football players experience pain, sometimes severe, that lasts for the rest of their lives. Many players require surgery, even multiple surgeries, for injuries experienced years earlier.

Interestingly, newspaper reporters who have interviewed former football players who are crippled or in pain as a result of their former sport find that a player will never (or virtually never) express regret over his choice of career. The players often state that the thrill of playing football was worth the price of a lifetime of subsequent pain.

Deaths and long-term disability attributed to illegal use of anabolic steroids have become a new factor in this picture, starting in about the 1990s.

Instances of heat-related death, especially during professional practice sessions, have begun receiving press attention in the decade of the 2000s, and led to new standards intended to respond cautiously to possible danger signs that traditionally had been ignored. There is also the prospect that conventional first-aid technique has been in error, and an apparatus to circumvent this: apparently efforts to cool an overheated patient quickly, by wetting a large fraction of the body, are misguided, with the sudden chilling of the skin causing the body to reduce superficial circulation, and making that chilling near the surface ineffective at cooling the core of the body and thus the brain. A device suitable for professional teams has been developed, that provides for rapid cooling of small areas of skin where large blood vessels are near the surface, and is proposed as a means of cooling the blood quickly without evoking the reflex of isolating the body surface from the core.

What's it all about?

Football is in many ways a unique sport. George Carlin has monologized at length on its contrasts with baseball, which is traditionally called "the American pastime": Football is about "ground control" and played on a "gridiron" of exact dimensions, while baseball is about "going home," and played in "parks" that are all different from one another, and so on. Such observations, however humorous, would be widely regarded as at least hints about some of the nature and significance of the game.

Character building

It is a widespread American doctrine that participation in team sports, including football in particular, inculcates worthwhile habits and values in the players. Leadership (at least for quarterbacks and exemplary players), identification with a group, aggressiveness where called for, the setting of personal goals, and sustaining commitment to these, are often mentioned.

Football scandals

There is a long history in the second half of the 20 century of controversy over the tension in college football between values important to the institution's academic mission and the team's win-and-loss record. Many observers attribute to football skill an excessive role in gaining admission for prospective players; they by and large regard this as an ongoing scandal. Measures that are seen as effective in maintaining players' academic eligibility but not in furthering their graduation or competence in their fields of study attract similar criticism.

In the decade of the 2000s, the increasing economic stakes in sports, changed attitudes outside football regarding acceptable behaviour towards women, and the perception of uncontrolled use of steroids, all have played a part in an increase in public concern about football's role. Many suggest that the status and other rewards accruing to players encourages arrogance in general, and in particular, both an assumption of privilege and an expectation of immunity from consequences. It is also suggested that

• steroid-using players are markedly more aggressive both on and off the field,
• their teammates and opponents grow accustomed to excessive aggression, and
• both groups are predisposed to treat women they encounter, especially in the presence of their sports colleagues, in a disrespectful, aggressive, and sometimes sexually coercive manner.

See also

• American Football League
• Arena Football League
• National Football League
• National Women's Football Association
• German Football League
• American football glossary
• List of American football players
  • Pro Football Hall of Fame
• Football
  • Canadian football
  • Comparison of Canadian and American football
  • Rugby football
• List of defunct sports leagues
• Fantasy Football
• Flag football
• Shotgun formation

External links

• NFL History and the basics
• NFL Digest of Rules - (a basic guide)
• NCAA Playing Rules (complete college football rules are available as a pdf file)
• About anabolic steroids
• Movie of 1903 football game between the University of Chicago and the University of Michigan

• American football
• Ball games