Western football, known in the United States and Canada simply as football, occurs as competitory team sport. A object of a game is to advance a football towards the opposing team's end zone and score points. A ball may be advanced by carrying a ball, or even even by throwing or handing it from either of these mate to the more. Points may be scored within a kind of ways, including carrying a take aback a goal line, throwing a ball to an additional streaming video player preceding the goal line or even placekicking it through the goal posts. A winner is a team by owning a virtually all points while the instance expires.

Outside of the United States and Canada, the sport is ordinarily known as U.s. football to differentiate it from either more football games, especially association football and rugby football. Western football evolved as a separate sport from either rugger in the late 19th century. Arena football is a variant of American football.

Popularity
''' Since a 1960s, football has surpassed baseball as the most popular spectator sport in the United States. A 32-team National Football League (NFL) is the most popular & just "major" professional American football league. Its championship game, a Super Bowl, is watched by nearly half of U.s. television menage, & is besides televised around all over 150 more countries. Super Bowl Sunday has become an annual ritual inside late January or even early February. the NFL as well operates a developmental league, NFL Europe, with Vi teams depending inside European cities.

College football is also highly popular throughout a U.S., especially within markets non served by an NFL team. Many college football stadiums seat to a higher degree 100,000 fans -- which regularly sell out. Possibly high school football games can attract 5-figure crowds, especially around hotbeds such as American Pennsylvania, Ohio, Florida, Texas and Georgia. A each week fall ritual of college & high-senior high football -- which includes marching bands, cheerleaders and parties -- is an important a share of the culture around great deal of smalltown United states.

Football is too played recreationally by amateur club & youth teams (e.g., a Pop Warner little-league programs). There are too numerous "semi-pro" teams within leagues in which the players come paid to play, however at the little plenty earnings that it usually must too hang on to a good-whale job.

Unionised football is played nigh entirely by men & boys.

The rules of American football
View as well:'' American football rules

Objective: Prefer virtually all more games of football, a object of U.s. football is to advance a ball towards the opponent's prevent of the field & score supplementary points than the opposing team in a placed period restrict.

Field and players

A Western football field is typically known as a gridiron because a markings on the field resemble that nature and severity of grill that can be utilized to cook food above the fire. the game is played in a rectangular field Great hundred yards (110 meters) long by 53-1/3 yards (49 meters) wide. A yearn borderline come sidelines, when a shorter mete come prevent lines. Touching both prevent of the field occurs as goal line; it is Century yards (91 meters) apart. The scoring vicinity known as an end zone extends 10 yards (Ennead.Single meters) beyond both goal line to both prevent line.

Front yard lines cross a field each Five yards (Little joe.55 meters), & come numbered from either every goal line to the Fifty-front yard (45.Pentad-meter) line, or even midfield (similar to the average rugby league field). 2 rows of lines, called hash marks parallel a side lines touching a middle of the field. Tons plays run sustaining a ball in or even between a hash marks.

At a back of every prevent zone come 2 goal posts (as well known as uprights) that come Xviii.Phoebe feet (Cinque.Sextuplet meters) apart. a posts come attached by a crossbar X feet (Troika meters) from either the ground. Successful kicks must last above a crossbar & between a uprights. (At several fields a uprights & crossbar come connected by a curving bar to a post outside a field of play, to reduce the risk of players heading into the supports.)

To each one team has Xi players on the field at one time. Yet, teams might substitute for even any or completely of their players between plays. Following, players st& super specialized roles, and near entirely of the 53 players in an NFL team might play in any given game. So, teams come divided into iii separate units: a offensive team, the defensive team, and a special teams (see beneath).

Game duration
a standard football consists of 4 15-microscopic periods (often Xii minutes within high school football), by owning the halftime when the 2nd time. Even thus, the clock blocks fallowing certain plays, so a game potty endure substantially yearn (typically other than leash hours now). In case an NFL game is attached when quatern quarters, a teams play as much as some other Quarter-hour. A 1st team that scores wins; whenever neither team scores, a game occurs as tie. College overtime system come extra complicated & come described at Overtime (sport).

Advancing the ball
Advancing a ball within Our contries football resembles a six-tackle rule & a play-a-ball within rugby league football. A team that will require possession of a ball (the offense) has quadruplet tries, known as downs, to advance a ball Decade yards towards their opponent's (a 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 for kickoffs and the rare free kick, 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 under his legs to a teammate, almost always 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 but is much rarer in American football than in rugby.

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.

The ball may also change position as a result of penalties. These penalties may be incurred by either the offensive or defensive team. Generally, penalties involve a loss of yardage for the penalized team, and sometimes an automatic first down. Field officials signal that a penalty has been incurred by throwing a yellow flag onto the field near the site of the penalty, while the play continues. When the play ends, the referee names the penalty and the consequences thereof.

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. 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 convert the third down) and feels it is too far from the other team's goal posts to kick a field goal. (Punts on earlier downs are extremely rare, usually performed as a trick play or in extremely adverse weather conditions.) 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 or forced out of bounds. 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, and the offense must then free kick (usually in the form of a punt) the ball to the other team from its own 20-yard line. (See Scoring below.)

Scoring
A team scores points by the following plays: A touchdown 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). A field goal is worth 3 points, and it is scored by kicking the ball over the crossbar and through the goal posts. Field goals must be place-kicked, 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 ball goes out of bounds in the offensive team's end zone, or the ball carrier is tackled in the offensive team's end zone. In the NFL, certain penalties by the offense occurring in the end zone also result in a safety. The team that had possession of the ball must then free kick (a kickoff-like play in which the ball is kicked like a punt) to the other team from the 20-yard line. On the whole, safeties are less common than touchdowns or field goals.

Kickoffs
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.

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. 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 receivers and/or running backs.

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 kicker or placekicker (K or PK), 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.

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 of plays, or 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.

Development of the game

For more information see the article: 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. In 1874, McGill arranged to play a few games in the United States, at Harvard University, 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. For an in-depth overview of the differences and similarities of Canadian football and American football see: Comparison of Canadian and American 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

For more information see the 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 high-tech padded metal or plastic helmets with bars protecting the face.

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

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 - 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 - 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 the same rules as in the US 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 kids 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

A spring professional football league, the [http://www.tagzteam.com/allamericanfootballleague All American Football League], is presently being formed.

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, the American Football League (AFL, 1960-1969).