American Football Database

A diagram showing an "I Formation" on offense and a 4-3 Formation on defense

In American football, each team has eleven players on the field at one time. Because the rules allow unlimited substitution between plays, the types of players on the field for each team differ depending on the situation. At the college and National Football League levels, most play only offense or only defense, with "two-way" players being a thing of the past.


The offensive team or offense in football is the team that begins a play from scrimmage in possession of the ball. A play usually begins when the quarterback takes a snap from the center and then either hands off to a running back or a receiver, passes to a receiver or a running back, runs the ball himself, spikes the ball or takes a knee. Also, the center may snap the ball directly to a running back or receiver, usually from a Wildcat formation, where a running back or receiver takes the place of the quarterback in a shotgun formation.

The purpose of the spiking the ball is to stop the game clock if the offense is running out of time. The purpose of taking a knee is to allow the clock to run with minimal risk of turning the ball over. If a player runs the ball and stays in bounds, or if a player receives a pass and stays in bounds (this has the same effect as taking a knee), then the clock keeps ticking. But if a player running the ball goes out of bounds, or there is an incomplete pass, then the clock stops.

The goal of the offensive team is to earn points for the entire team. The offensive earns points by scoring a touchdown. A touchdown results in 6 points. After the offense scores a touchdown, the special teams comes onto the field to attempt an extra point. An extra point results in 1 point. The offensive team, however, can also help the team score by getting good field position for an attempt at a field goal. A field goal earns the team 3 points.

The offensive unit in football consists of a quarterback, linemen, running backs, tight ends, and wide receivers. The function of most of the linemen is to block. The offensive line consists of a center, two guards, two tackles and one or two tight ends. Backs include running backs who frequently carry the ball and receive swing passes and screens, and a fullback, who usually blocks, and occasionally carries the ball or receives a pass. The primary function of the wide receivers is to catch passes.

The makeup of the offense and how it operates is governed by the head coach or offensive coordinator's offensive philosophy.

  • Center (C) — the center performs the normal blocking functions of all linemen and is the player who puts the ball in play by means of the snap. On many teams the Center will be one of the "Team Captains" and depending on the amount of autonomy allowed by the team, some centers are responsible for coordinating and directing the efforts of the other members of the Offensive Line.
  • Offensive guard (G) — the two guards are the offensive linemen directly on either side of the center and inside the tackles. 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" - moving around behind the other offensive linemen upon the start of the play - in order to block a player on either side of the center, in an inside running play called a "trap" or an outside running play called a "sweep."
  • Offensive tackle (T)—the offensive tackles play on the outer side of each guard. 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 blindside, and is often faster than the other offensive linemen to stop 'speed rushers' at the Defensive End position. Like a guard, the tackle may have to "pull," on a running play, when there is a tight end on his side.
The description above of the guard and tackle positions apply only to a line that is balanced (has equal numbers of players on both sides of the player who is to snap the ball). In an unbalanced line, there may be players designated "guard" or "tackle" next to each other.
Offensive linemen cannot catch the ball but on rare occasions they are allowed and sometimes even run the ball. In most circumstances, however, they do not. Except for the snap by the offensive center as each play from scrimmage starts, ordinarily the only way an offensive lineman can get the ball during a play is by picking up a fumble. Players who normally play on the offensive line may only handle the ball during normal play if they line up in another elligible position, for example at tight end or fullback.
  • Tight end (TE) — Tight ends play on either side of, and roughly next to, the tackles. They are a mix between a blocker and a pass receiver. If an end moves away from the tackle, he is called a split end. Modern formations typically have one tight end and one split end. Many modern formations also forgo tight ends and replace them with wide receivers. Sometimes a formation is referred to as having "three tight ends." This means in reality that an additional blocker (a wingback or an eighth lineman) has been substituted for a wide receiver. This would be done as in short-yardage situations where receivers are not needed.
  • Wide receiver (WR) — The wide receivers are speedy pass-catching specialists. However, they can be bigger if they still can get open and catch the ball. Their main job is to run pass routes and get open for a pass, although they are occasionally called on to block. A wide receiver may line up on the line of scrimmage and be counted as one of the necessary seven players on the line in a legal formation (a split end), or he may line up at least one step behind the line of scrimmage and be counted as being in the backfield (a flanker if he is on the outside, a slot if he is not the outside receiver but is away from the tackle, or a wingback if he lines up near [usually adjacent to and just behind] the tackle). There are generally two types of wide receivers, "speed" and "possession." A speed receiver's primary function is to use his burst speed (speed from a standing start), to stretch the field (by forcing his coverage to retreat further into the back field in the hope that at the snap of the ball they [the pass coverage] will already be near where the receiver will catch the ball). The defense has to estimate where the speed receiver will move to; and may have to pull away an eighth defensive man near the line of scrimmage who would otherwise move against the quarterback. A possession receiver is generally the more sure-handed of the two types and is used to keep possession of the ball by making catches that gain first down less yardage; but he usually lacks the speed to attack a defensive backfield. Passing long (deep into the backfield) to the possession receiver is a risk because equally quick or quicker defensive backs may be able to reach this receiver deep in their territory and (if they are so skilled), legally break up his reception of the ball. Also, if a pass is not properly thrown, is tipped, is carried by the wind (in an outdoor game), or the pass route is misunderstood between the passer and the receiver, the defense may use their equal or superior speed to make a clean interception of the ball.
  • Fullback (FB) — Positioned behind the middle of the line, a fullback may do some running, some blocking, and some short receiving. A classic fullback is more of a power runner than a running back. Many modern formations do not use a fullback. Most plays utilizing the fullback call for him to block, generally by running the planned rushing route behind the opening his offensive line has made in the opposite defensive lineup; and taking the block of the first linebacker(s) who tries to seal the gap the offensive line has made in the defense. By doing this the Fullback creates a path for the running back to run while having the ball. The greatest yardage can be gained by the running back when the fullback blocks, but concentrates on keeping on moving downfield with the running back advancing behind him. Should this blocking protection for the runner remain intact until the rushing convoy reaches the rear of the defensive secondary (the linebackers), and with the running back still on his feet and running downfield, one of the most memorable plays in the sport can be observed--that of an open-field run for long yardage or a touchdown.

Penn State Nittany Lions quarterback #14 Anthony Morelli hands the ball off to his running back #33 Austin Scott in their 2007 season opener.

  • Running back (RB) — The modern term for the position formerly called "halfback" and often referred to as a "tailback." The running back carries the ball on most running plays and is also frequently used as a short-yardage receiver. Running backs, along with the wide receivers, are generally the fastest players on the offensive team. Most of them tend not to run straight ahead, preferring to make quick cutbacks to try to find holes in the defense. The running back is in fact looking for a clear path (of any shape) to the gap between the defensive secondary (the linebacker(s)) and the defensive backfield. A modern running back still on his feet in this gap can cross the distance down field before he can be tackled by the defensive secondary (he is usually much faster than they are). His small size, his speed, and his physical strength make it very difficult for defensive backs to catch him, or to legally bring him down if they do catch up to him on the run. A new formation that is becoming more popular in football has the running back lined up as the quarterback and the quarterback split out as a receiver. This formation is known as "wildcat", and the running back lines up behind the center and receives the snap of the ball. The reason running backs are injury prone and rarely have long careers in the game is either the initial hits they receive when they run directly into the defensive line; or else hits taken from the larger linebackers while on the run which do much damage, especially to the knees and ligaments (joints). "Fullback" is now regarded as a separate position from running back, with a substantially different role (especially in the NFL).
  • Quarterback (QB) — Typically the quarterback is positioned to take the football when the ball is snapped (handed or passed) between the center's legs. Recent usage refers imprecisely, however, to a player who is positioned behind the center at any distance, calls signals, is not the usual punter or place kick holder, and usually takes the snap as "quarterback" regardless of exact position, because those functions have typically been performed by quarterbacks. Typical play from formations where the quarterback takes the snap proceeds by the quarterback either handing the ball off to a running back to run, throwing the ball downfield, or running personally.

Teams can vary the number of wide receivers, tight ends and running backs on the field at one time. Football rules limit the flexibility of offensive formations. Seven players must line up on the line of scrimmage, and only the two at the end are eligible to catch passes. Sometimes, offensive lineman can declare eligibility and become "tackle eligible." Jumbo Elliott and Dan Klecko are two tackles who have caught touchdowns while being tackle eligible. Typical formations include:

  • One running back, two tight ends and two wide receivers.
  • Two running backs, one tight end and two wide receivers.
  • One running back, one tight end and three wide receivers.
  • One running back, no tight end and four wide receivers.
  • No running backs, no tight end and five wide receivers.


The defensive team or defense is the team that begins a play from scrimmage not in possession of the ball. The object of the defensive team is to prevent the other team from scoring. Unlike many sports, defense in American football can be very aggressive, seeking to attack the opposing quarterback and to push the offense back from the line of scrimmage. The sign that the defensive goal has been accomplished is recovering possession of the football before the offensive team scores, which usually involves the offensive team punting the ball on fourth down. Other possibilities include having the ball turned over on downs, getting an interception or recovering a fumble. Also, if an offense advances down-field and into the red zone (within the 20-yard line of the defense) and is threatening to score a touchdown, the defense can consider its goal accomplished if it forces the offense to settle for a field goal (three points) rather than a touchdown (six points). Many teams operate specific defensive plays for the so called 'Red Zone' specifically to achieve this.

Unlike the offensive team, there are no formally defined defensive positions. A defensive player may line up anywhere on his side of the line of scrimmage and perform any legal action. Most sets used in football, however, include a line composed of defensive ends and defensive tackles and (behind the line) linebackers, cornerbacks, and safeties.

Defensive ends and tackles are collectively called defensive linemen, while the cornerbacks and safeties are collectively called defensive backs, or the secondary.

  • Defensive end (DE) — The two defensive ends play on opposite outside edges of the defensive line. Their function is to attack the passer or stop offensive runs to the outer edges of the line of scrimmage (most often referred to as "containment"). The faster of the two is usually placed on the right side of the defensive line (quarterback's left) because that is a right-handed quarterback's blind side.
  • Defensive tackle (DT) — Sometimes called a defensive guard, defensive tackles are side-by-side linemen who are between the defensive ends. Their function is to rush the passer (if they can get past the offensive linemen blocking them), and stop running plays directed at the middle of the line of scrimmage. A defensive tackle who lines up directly across from the ball (and therefore is almost nose-to-nose with the offense's center) is often called a nose tackle or nose guard. The nose tackle is most common in the 3-4 defense and the quarter defense. Most defensive sets have from one to two defensive tackles. Sometimes, but not often, a team will employ three defensive tackles.
  • Nose guard (NG) — Sometimes called a middle guard, the nose guard lines up directly opposite the offensive center, or over the center's "nose." Nose guards tend to be shorter than most other defensive linemen. They are typically very strong and their responsibility is to stop runs down the middle and draw double teams. Extremely quick nose guards are sometimes used to shoot through the offensive line before it can react. They then sack the quarterback or make a tackle shortly after a hand off. This is rare, however, because most defensive linemen are not quick enough to consistently shoot the gaps between the individual offensive linemen. "Nose guard" is often a term incorrectly applied to the defensive tackle in a 3-4 defensive scheme. This position is known as a nose tackle.
  • Linebacker (LB) — 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. Most defensive sets have between two and three linebackers. Linebackers are usually divided into three types: strongside (left or right outside linebacker: LOLB or ROLB); middle (MLB); and weakside (LOLB or ROLB). The strongside linebacker usually lines up across from the offense's tight end; he is usually the strongest LB because he must be able to shed lead blockers quickly enough to tackle the running back. The middle linebacker must correctly identify the offense's formations and what adjustments the entire defense must make. Because of this, the middle linebacker is nicknamed the "quarterback of the defense." The weakside linebacker is usually the most athletic or fastest linebacker because he usually must defend an open field.
  • Cornerback (CB) — Typically two players who primarily cover the wide receivers. Cornerbacks attempt to prevent successful quarterback passes by either swatting the airborne ball away from the receiver or by catching the pass themselves. In rushing situations, their job is to contain the rusher.
  • Safety (FS or SS) — The safeties are the last line of defense (farthest from the line of scrimmage) and usually help the corners with deep-pass coverage. The strong safety (SS) is usually the larger and stronger of the two, providing extra protection against run plays by standing somewhere between the free safety and the line of scrimmage. The free safety (FS) is usually the smaller and faster of the two, providing variable and extra pass coverage. Traditionally, teams have looked for safeties with reputations as hard hitters. More recently, however, teams have been looking for hybrid safeties who can do both jobs, as in a cover 2 defense, when the strong safety has a greater role to play in coverage. Safeties are also used in a variety of blitzes.

Defensive back — It is not a specific position; however, it is any position besides the line, including cornerbacks, safeties, etc., that is behind the line of scrimmage.

  • Nickelback and Dimeback — In certain formations one extra (a fifth) defensive back (called a nickel defense), two extra (a sixth) DBs (called a Dime package), three extra (a seventh) DBs called a Quarter, or even four extra (an eighth) DBs called a Half Dollar may be used to augment the backfield or defensive line. Nickelbacks, dimebacks, and Defensive Quarterbacks are usually used to defend pass plays with extra receivers, but they can also be used to rush quarterbacks or running backs more quickly than linemen or most linebackers can. A starting cornerback who is good at blitzing and tackling will sometimes be referred to as a nickelback to distinguish them from cornerbacks.

Typical defensive formations include:

  • Five defensive linemen, two linebackers and four defensive backs (the 5-2 formation)
  • Five defensive linemen, three linebackers and three defensive backs (the 5-3 formation)
  • Four defensive linemen, three linebackers and four defensive backs (the 4-3 formation)
  • Four defensive linemen, four linebackers and three defensive backs (the 4-4 formation)
  • Three defensive linemen, four linebackers and four defensive backs (the 3-4 formation)
  • Three defensive linemen, three linebackers and five defensive backs (the 3-3-5 formation)
  • Four defensive linemen, two linebackers and five defensive backs (the Nickel formation)
  • Four defensive linemen, one linebacker and six defensive backs.(the Dime formation)
  • Three defensive linemen, one linebacker and seven defensive backs (the Quarter formation)
  • Three defensive linemen, no linebackers and eight defensive backs (the Half Dollar formation)

Special teams

"Special teams" redirects here. For the ice hockey definition of "special teams," see powerplay and short handed.

Special teams are units that are on the field during specific situations. They include a kickoff team, a kick return team, a punting team, a punt blocking and return team, a field goal and extra point team, a field goal blocking team and "hands team" used for onside kicks to prevent the kicking team from recovering a kick, usually by recovering the ball themselves. Though fewer points are scored on special teams than on offense, special teams play determines where the offense will begin each drive, and thus it has a dramatic impact on how easy or difficult it is for the offense to score.

Because these aspects of the game can be so different from general offensive and defensive play, a specific group of players is drilled in executing them. Most special teams players are second- and third-string players from other positions, but there are also specialized players on these teams, including:

  • Kicker (K) — Handles kickoffs and field goal attempts, and in some leagues, punts as well.
  • Holder (H) — Usually positioned 7-8 yards from the line of scrimmage, he holds the ball for the placekicker to kick. The holder is often a backup quarterback or a punter.
  • Long snapper (LS) — A specialized center who snaps the ball directly to the holder or punter. All thirty-two NFL teams have specialized players just to long snap.
  • Kick returner (KR) — Returns kickoffs, generally is also a wide receiver or cornerback.
  • Punter (P) — Kicks punts. In leagues other than the NFL, the kicker often doubles as the punter.
  • Upback — A blocking back who lines up approximately 1-3 yards behind the line of scrimmage in punting and kneel situations. His primary job is to act as a second line of defense for the punter. Upbacks can receive a direct snap in fake punt situations.
  • Punt returner (PR) — Returns punts. Often the same player as the kick returner, although not necessarily so.
  • Gunner — A player on kickoffs and punts who specializes in running down the field very quickly in an attempt to tackle the kick returner or the punt returner.
  • Wedge Buster — A player whose goal is to sprint down the middle of the field on kickoffs. While ideally, their goal is to reach the kick returner, their immediate goal is to disrupt the wall of blockers (the wedge) on kickoffs, preventing the returner from having a lane in which to get a substantial return. Being a wedge buster is a very dangerous position since he may often be running at full speed when coming into contact with a blocker. This role has changed in the wake of the NFL largely banning wedges.

See also



External links