American football positions

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.

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 offensive line consists of: The center is the player who begins the play from scrimmage by snapping the ball to the quarterback.

The center often also has the responsibility to call out blocking assignments and make last second adjustments depending on the defensive alignment.

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.

Tight ends are considered hybrid players because they are a cross between a wide receiver and an offensive lineman.

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.

Over time, however, defensive roles have become defined into three main sets of players that encompass several individual positions.

Their function is to rush the passer and stop running plays directed at the middle of the line of scrimmage.

Their function is to clog the middle of the offense's line and stop most run plays (more commonly fullback dives, plunges and sneaks).

This position is the most physically demanding, due to being forced into constant double or triple teams, and needing enough speed to collapse the interior of the offensive line.

Sometimes, nose tackles are used in 4-3 defenses and are either positioned on the quarterbacks blind side, or directly in front of the center.

Their function is to attack the passer or stop offensive runs to the outer edges of the line of scrimmage, which is often referred to as containment.

Linebackers play behind the defensive line and perform various duties depending on the situation, including rushing the passer, covering receivers, and defending against the run.

Some teams keep their outside linebackers on the same side of the field at all times while others define them as playing on either the strongside (SLB) or the weakside (WLB).

They 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.

The free safety (FS) is often the smaller and faster of the two, and is typically the deepest player on the defense, providing help on long pass plays.

Placekickers, colloquially called simply a kicker, handle kickoffs, extra points, and field goals.

All three situations require the kicker to kick the ball off the ground, either from the hands of a holder or off a tee.

Due to their specialized nature and the limited number of active roster spots, kickoff specialist are rare.

The holder is usually positioned 7–8 yards from the line of scrimmage and holds the ball for the placekicker to kick.

The player occupying this position is often a backup quarterback or a punter because of their good hands, feel for the ball, and experience taking snaps from a long snapper or center during plays from scrimmage.

A holder is occasionally used on kickoffs if the weather or field conditions repeatedly cause the ball to fall off the tee.

The long snapper is a specialized center who snaps the ball directly to the holder or punter.

Long snappers are generally the size of tight ends or linebackers, as they not only have to be big enough to block for the punter or kicker, but also athletic enough to run down the field on coverage to try to tackle the return man.

Their primary role is to act as the last line of defense for the punter; however, upbacks occasionally receive the snap instead on fake punts and will either pass or run with the football in those situations.

A gunner is a player on kickoffs and punts who specializes in running down the field very quickly in an attempt to tackle the returner.