American football positions


In American football each team has 11 players on the field at one time. The specific role that a player takes on the field is called their position. Under the modern rules of American football, teams are allowed unlimited free substitutions; that is, teams may change any number of players after any play, at any point in the game. This has resulted in the development of three task-specific "platoons" of players within any single team: the offense, the defense, and the so-called 'special team'. Within these three separate "platoons", various specific positions exist depending on what each player's main job is.

Offense

In American football, the offense is the term used to describe the team which has possession of the ball. It is their job to advance the ball towards the opponent's end zone to score points. Broadly, the eleven players of the offense are broken into two groups: the five offensive linemen, whose primary job is to block opponents and protect their quarterback, and the six backs and receivers whose primary job is to advance the ball either running with the ball or passing it. The backs and receivers are also commonly known as skill position players or as eligible receivers. Offensive linemen are not eligible to advance the ball past the line of scrimmage during a play.
The organization of the offense is strictly mandated by the rules of the sport; there must be at least seven players on the line of scrimmage and no more than four players behind it. The only players eligible to handle the ball during a normal play are the backs and the two players on the end of the line. The remaining players are "ineligible" to catch forward passes, so they usually only block. Within these strictures, however, creative coaches have developed a wide array of offensive formations to take advantage of different player skills and game situations.
The following positions are standard in nearly every game, though different teams will use different arrangements of them, dependent on their individual game plans.

Offensive (interior) line

The offensive line is primarily responsible for blocking the defensive line of the opposition, in order to protect their own quarterback. During normal play, offensive linemen do not handle the ball, unless the ball is fumbled by a ball carrier, a pass is deflected, or when a player who is normally an offensive lineman takes a different position on the field. The offensive line consists of:
;Center
;Offensive guard
;Offensive tackle

Backs and receivers

The six backs and receivers are those that line up outside or behind the offensive line. There are four main positions in this set of players:
;Quarterback
;Running back
;Wide receiver
;Tight end
Depending on the style of offense the coaches have designed, the game situation, and the relative skill sets of the players, teams may run formations which contain any number of running backs, wide receivers, and tight ends, so long as the mandated "four backs and seven on the line" rule is followed. For many years, the standard set consisted of the quarterback, two running backs, two wide receivers and a tight end. Modern teams show a wide variety of formations, from a "full house" formation with three running backs, two tight ends, and no wide receivers, to "spread" formations featuring four or five wide receivers, sometimes without any running backs.

Defense

The defensive team or defense is the team that begins a play from scrimmage not in possession of the ball. The objective of the defensive team is to prevent the other team from scoring, and win possession of the ball for their side. The defense accomplishes this by forcing the offense to turn the ball over, either by: preventing them from achieving a first down and thus forcing them to punt, forcing the offense to fumble or throw an interception, or, more rarely, forcing a turnover on downs.
Unlike the offensive team, the rules of the sport do not restrict the defensive team into certain positions. A defensive player may line up anywhere on his side of the line of scrimmage and perform any legal action. Over time, however, defensive roles have become defined into three main sets of players, and several individual positions.

Defensive line

Like their offensive counterparts, defensive linemen line up directly on the line of scrimmage, close to the ball. There are two positions usually considered part of the defensive line:
;Defensive tackle ;
;Defensive end
Often, a defensive lineman will have their hands on the ground, in a three- or four-point stance before the ball is snapped; this distinguishes their pre-snap stance from a linebacker, who begins in a two-point stance.

Linebackers

s play behind the defensive line and perform various duties depending on the situation, including rushing the passer, covering receivers, and defending against the run.
; Middle linebacker
; Outside linebacker

Defensive backs

s, also known as the "secondary", play either behind the linebackers or set to the outside, near the sidelines. Defensive backs are primarily used to defend against pass plays. Defensive backs also act as the last line of defense on running plays and need to be able to make open field tackles, especially when the ball carrier has gotten past the other defenders. A normal complement of defensive backs includes two cornerbacks and two safeties, though specialty defensive backs can be brought in in place of linebackers and defensive linemen, when there is a need to cover additional pass receivers.
;Cornerback
;Safety
;Nickelback and dimeback
Defensive formations are often known by a numerical code indicating the number of players at each position. The two most common formations are the 3–4 defense and the 4–3 defense, where the first number refers to the number of defensive linemen, and the second number refers to the number of linebackers. Thus, a 3–4 defense consists of three defensive linemen, four linebackers, and four defensive backs

Special teams

Special teams are units that are on the field during kicking plays. While many players who appear on offensive or defensive squads also play similar roles on special teams there are some specialist roles which are unique to the kicking game.
;Kicker
;Holder
;Long snapper
;Punter
;Kickoff specialist
;Kick returner and punt returner
;Upback
;Gunner
;Jammer