American football positions
In American football, the specific role that a player takes on the field is referred to as their position. Under the modern rules of American football, both teams are allowed 11 players on the field at one time and have "unlimited free substitutions", meaning that they may change any number of players during any dead ball situation. This has resulted in the development of three task-specific "platoons" of players within any single team: the offense, the defense, and special teams, who play in all kicking situations. Within these three separate platoons, various positions exist depending on the jobs that the players are doing.
Offense
In American football, the offense is the team that has possession of the ball and is advancing toward the opponent's end zone to score points. The eleven players of the offense can be separated into two main groups: the five offensive linemen, whose primary job is to block opponents and protect their quarterback, and the other five backs and receivers, whose primary job is to move the ball down the field by either running with it or passing it.The rules of the sport strictly mandate the organization of the offense: there must be at least seven players on the line of scrimmage and no more than four players, known collectively as backs, behind it. The only players eligible to handle the ball during a normal play are the backs and the two players on the ends of the line, known as the ends. These players make up the skill positions and are also referred to as eligible receivers or eligible ball carriers. The remaining players, known as interior linemen, are ineligible to catch forward passes. Within these structures, 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, depending on their individual game plans.
Offensive line (OL)
The offensive line is primarily responsible for blocking the defensive line of the opposition 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 a player who is normally an offensive lineman takes a different position on the field. The offensive line consists of:Center (C)
The center is the player who begins the play from scrimmage by snapping the ball to the quarterback. As the name suggests, the center usually plays in the middle of the offensive line, though some teams may employ an unbalanced line where the center is offset to one side. Like all offensive linemen, the center has the responsibility to block defensive players. The center often also has the responsibility to call out blocking assignments and make last-second adjustments depending on the defensive alignment.Offensive guard (OG)
Two guards line up directly on opposite sides of the center. Like all interior linemen, their function is to block on both running and passing plays. On some plays, rather than blocking straight ahead, a guard will pull, during which the guard comes out of their position in line to lead block for a ball carrier, on plays known as traps, sweeps for outside runs, and screens for passing plays. In such cases, the guard is referred to as a pulling guard.Offensive tackle (OT)
Two tackles play outside of the guards. Their role is primarily to block on both running and passing plays. The area from one tackle to the other is an area of close line play in which blocks from behind, which are prohibited elsewhere on the field, are allowed. For a right-handed quarterback, the left tackle is charged with protecting the quarterback from being hit from behind, known as the blind side, and this is usually the most skilled player on the offensive line. Like a guard, the tackle may have to pull on a running play when there is a tight end on their side. Tackles typically have a taller, longer build than interior offensive linemen, due to the need to keep separation from defensive linemen in pass blocking situations. They also tend to have quick footwork skills, often engaging against containing or rushing defensive ends.Skill positions
Offensive positions that handle the ball and are primarily responsible for advancing yards and scoring points are known as the skill positions. They include quarterbacks, backs, wide receivers, and tight ends.Quarterback (QB)
The quarterback is the player who receives the ball from the center to start the play. Considered the most influential position on the offensive side because his team's progress down the field is dependent on his success, the quarterback is responsible for receiving the play from the coaches on the sideline and communicating the play to the other offensive players in the huddle, and serves as the leader of the team's passing game. The quarterback may need to make late changes to the intended play at the line of scrimmage, known as an audible, depending on the defensive alignment. At the start of the play, the quarterback may be lined up in one of three positions. If they are positioned directly behind and in contact with the center and receive the ball via the direct hand-to-hand pass, they are said to be "under center". Alternatively, if they are lined up some distance behind the center, they are said to be either in shotgun formation or in pistol formation, with shotgun generally further back than pistol. Upon receiving the ball from the center, the quarterback has three basic options to advance the ball: they may run the ball themself, hand it to another eligible ball carrier to run with it, or execute a forward pass to a player further up the field.Backs (RB/FB)
s are players who line up behind the offensive line in a position to receive a hand-off from the quarterback and execute a rushing play. Anywhere from zero to three running backs may be utilized on a play; a formation with no running backs is often called an empty backfield. Depending on where they line up and what role they have, running backs come in several varieties. The tailback, also known as the halfback, is often a team's primary ball carrier on rushing plays. They may also catch passes, often acting as a check-down or safety valve when all other receivers on a pass play are covered. A wing-back or a slot-back is a term for a running back who lines up behind the line of scrimmage outside the tackle or tight end on either side of the offensive line. Slot-backs are usually only found in certain offensive alignments, such as the . There also exists a similar position, known as the , which is actually considered a modification of the normal tight end position.The fullback is often larger and stronger than the tailback and acts primarily as a blocker, though the fullback may also be used for catching passes or for rushing as a tailback does. Fullbacks often line up closer to the line of scrimmage than tailbacks do to block for them on rushing plays.
Wide receiver (WR)
s are pass-catching specialists. Typically fast and tall, their main job is to run pass routes and get open for passes, although they are occasionally utilized as blockers. Wide receivers generally line up split wide near the sidelines at the start of the play. Wide receivers, like running backs, come in different varieties depending on exactly where they line up. A wide receiver who is directly on the line of scrimmage is called a split end and is counted among the seven required players on the line of scrimmage. A wide receiver who lines up behind the line and counts as one of the four backs is called the flanker. A wide receiver who lines up between the outermost wide receiver and the offensive line is said to be in the slot and is called the slot receiver. A wide receiver who can play running back is called a wide back.Tight end (TE)
s play on either side of the offensive line and directly next to the tackles. Tight ends are considered hybrid players because they are a cross between a wide receiver and an offensive lineman. Because they play next to the other offensive linemen, they are very frequently called on to block, especially on run plays. However, because they are eligible receivers, they may also catch passes. The position known as the H-back is a tight end who lines up behind the line of scrimmage, and is thus counted as one of the four backs, but their role is otherwise similar to that of other tight ends.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 that 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 and either one or no running backs.
Defense
The defensive team, simply known as the defense, is the team that begins a play from scrimmage without 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 by either preventing them from achieving a first down and forcing them to punt, forcing and recovering an offensive fumble, intercepting a pass, or more rarely, forcing a turnover on downs.Unlike the offensive team, the rules of the sport do not restrict the defensive team to 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 that encompass several individual positions.
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. Some defensive formations will directly indicate the number of defensive backs. The 3–3–5 defense, for instance, has 3 defensive linemen, 3 linebackers, and 5 defensive backs.