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American football




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.)

Popularity

Football is extremely popular in the US. In recent years it has surpassed
even 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.

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 popular in the US, particlarly as a
participation sport for children. 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.

Professional, college, and other leagues

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

   * Professional (NFL) football
   * 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
   * Amateur and youth league football
   * Flag football - non-tackle; almost exclusively amateur
   * Touch football - also non-tackle and almost exclusively amateur

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.

Object of the game

The object of the game is to advance the ball to the opponents' end of the
field and score points. The team with the most points when time has expired wins.

Duration, kickoffs and free kicks

The game is 60 minutes long, divided into two halves separated by a
halftime. Each half consists of two quarters, each 15 minutes long, between
which teams change ends of the field. Teams also change ends of the field at
halftime. If a game is tied at the end of regulation, overtime is played.
Overtime periods are "sudden death", meaning that the teams that scores
first, by any means, wins.

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.

Methods of scoring

Points can be scored in the following ways.

   * A field goal, worth 3 points, is scored by placing the ball on the
     ground and kicking it between the uprights of the goal posts. (If a
     field goal is missed, the ball is returned to the original line of
     scrimmage [in the NFL, the spot of the kick], and possession is given
     to the other team.)
   * A touchdown, worth 6 points, is achieved when a player has legal
     possession of the ball within the opponents' end zone.
   * One or two extra points may be scored following a touchdown. The team
     which scored the touchdown is given a conversion attempt (occasionally
     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. The defending team can never score during a conversion attempt
     by the other team.
        o An extra point, worth 1 point, is scored in the same way as a
          field goal is scored during regular play.
        o A two-point conversion is scored in the same way as a touchdown is
          scored during regular play.
   * A safety, worth 2 points, is scored when an opposition player attempts
     to run the ball out of his own end zone, and is either tackled or goes
     out of bounds before he has entered the field of play.

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.

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 quaterback, 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 short 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. 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.

Fourth down situations

If a team uses all four of its downs without gaining the yardage for a first
down, 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" - If the distance required for a first-down is short, a
     team may elect to go for it on fourth down, but it is often risky. 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 may try a "drop
     kick" -- that is, drop the ball and kick 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 the 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, and possession is given to the other team.
     (In the NFL, failed field goal attempts are spotted at the spot of the
     kick.)

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.

     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 when the ball is snapped, with the exception of the center.

Penalties against the offense

   * False start (5 yards) - a lineman moving before the snap in a way that
     simulates the start of the play
   * Illegal motion (5 yards) - having more than one back in motion at the
     snap
   * Illegal shift (5 yards) - not being set before the snap
   * Illegal formation (5 yards) - having less than 7 players on the line of
     scrimmage
   * Delay of game (5 yards) - allowing too much time to elapse before the
     snap
   * Ineligible receiver downfield (5 yards) - a lineman beyond the neutral
     zone prior to a forward pass
   * Illegal forward pass (5 yards and loss of down) - thrown from beyond
     the neutral zone, or a second forward pass on the same play.
   * Holding (10 yards) - illegal use of the hands or arms while blocking
   * Offensive pass interference (10 yards) - interfering with a defender
     attempting to catch a pass
   * Intentional grounding (10 yards and loss of down) - throwing the ball
     into the ground to avoid being tackled
   * Clipping (15 yards) - an illegal block from behind below the waist
   * Illegal block (15 yards) - usually a "crackback block".

Penalties against the defense

   * Offside (5 yards) - making contact with an offensive lineman before the
     ball is snapped. or being in the neutral zone when the ball is snapped.
     The offense can decline the penalty and take the yardage gained on the
     play.
   * Running into the kicker (5 yards) - during a kick from scrimmage
   * Pass interference - 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
   * Piling on (15 yards)
   * Roughing the kicker (15 yards) -
   * Roughing the passer (15 yards) - also called unnecessary roughness

Penalties against either team

   * Too many players on the field (5 yards)
   * Grabbing the face mask (5 or 15 yards) - if intentional, 15 yards; if
     unintentional, 5 yards. Just touching an opponent's face mask, without
     grabbing it, is not illegal.

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 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.

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