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 team with possession of the ball, which is trying to score), the defense (the team trying to prevent the other team from scoring, and to take the ball from them), 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.

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 six 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 end 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, dependent on their individual game plans.

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, (aside from the snap from center), 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:

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.

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 (for inside runs), sweeps for outside runs, and screens for passing plays. In such cases, the guard is referred to as a pulling guard.

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.