American football, known in the United States as simply football is a competitive team sport related to, derived from, and somewhat similar to, other forms of football, but differing from most of them in significant ways. (The one other form of football that differs only slightly from American football is Canadian football.)
baseball as the nation's most popular spectator sport. The professional league, the National Football League (NFL), which consists of 32 teams, is very popular. Its championship game, the Super Bowl is annually watched by nearly half of US television households, and is also televised in other countries. 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 colleges in lower NCAA divisions and the NAIA[?] (National Association of Intercollegiate Athletics[?]) have varsity football teams, as do most high schools. There are also amateur, club and youth teams (such as teams in the Pop Warner leagues).
In addition to those leagues and teams, now there is a yearly American Football World Cup, which is held every year, at the same time and at the same host country for both men's American football and women's American football. 2003's World Cup will be held in The Bahamas.
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 popular in the US, particlarly as a participation sport. It is played at all levels, youth, amateur, high school, college and professional. (see: football (soccer))
In this article, the word football refers to American football.
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.
NFL, college, high school, and amateur rules are similar, as were the rules of professional leagues that no longer exist. The Arena Football League (AFL, 1987-present) plays an indoor adaptation of American football. 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 American Football Conference (1946-1949), the American Football League (AFL,1960-1969-merged with the NFL in 1970), and the World League of American Football (WLAF,1991-1993-now NFL Europe). Since 2000, there has been a surge of women's professional leagues.
The Game Play in American football consists of a series of individual plays of short duration, between which the ball is not in play. Substitutions are allowed 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, the strategies are complex.
A kickoff is a special play used to start each half, and also used to restart the game following a field goal, or a conversion attempt following a touchdown. One team kicks the ball, usually from its own 30-yard line, although a kickoff may occur elsewhere due to a penalty 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) and in bounds at least 10 yards away. Once the ball has traveled 10 yards upfield it can be fielded by either team. 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 that is known as an onside kick[?].
A free kick is used to restart the game following a safety, which doesn't happen often. The team that was trapped in its own end zone, and therefore conceded two points to the other team, kicks the ball from its own 20-yard line. A free kick may be punted if the kicking team so chooses.
The Field The field is a rectangle 120 yards long and 53 1/3 yards 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 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, are 70-3/4 feet from the sidelines in the NFL. (Note: the hash marks are closer to the sidelines in college football) Every 5 yards, 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 18-1/2 feet, and the top of the crossbar is 10 feet 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.
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.
Advancing the ball There are two methods that can be used to advance the ball while still maintaining possession:
Things the offense may decide to do on fourth down:
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 units. Some players may only be used in certain situations. (for details see: offensive unit, defensive unit, special teams.)
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 a penalty against the offense. A penalty against the defense 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. A personal foul, which involves danger to another player, usually results in a 15 yard penalty.
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 by the Rugby Union code while Harvard played the Boston Game[?], which was closer to Association Football. 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 Union rules for their annual game. In 1876 Yale, Harvard, Princeton, and Columbia formed the Intercollegiate Football Association[?], which used the Rugby Union code, except for a slight differnce 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.
By the 1890s interlocking offensive formations such as the flying wedge 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. However, it was not until 1910, and after further deaths, that interlocking formations were outlawed.
The forward pass was introduced in 1906. In 1912 the field was changed to its current size, the value of a touchdown was increased to 6 points, and a fourth down was added. The game had achieved its modern form.