The quarterback, colloquially known as the "signal caller", is a position in gridiron football. Quarterbacks are members of the offensive platoon and mostly line up directly behind the offensive line. In modern American football, the quarterback is usually considered the leader of the offense, and is often responsible for calling the play in the huddle. The quarterback also touches the ball on almost every offensive play, and is almost always the offensive player that throws forward passes. When the QB is tackled behind the line of scrimmage, it is called a sack.
In gridiron football, a lineman is a player who specializes in play at the line of scrimmage. The linemen of the team currently in possession of the ball are the offensive line, while linemen on the opposing team are the defensive line. A number of NFL rules specifically address restrictions and requirements for the offensive line, whose job is to help protect the quarterback from getting sacked for a loss, or worse, fumbling. The defensive line is covered by the same rules that apply to all defensive players. Linemen are usually the largest players on the field in both height and weight, since their positions usually require less running and more strength than skill positions.
A cornerback (CB) is a member of the defensive backfield or secondary in gridiron football. Cornerbacks cover receivers most of the time, but also blitz and defend against such offensive running plays as sweeps and reverses. They create turnovers through hard tackles, interceptions, and deflecting forward passes.
Linebacker (LB) is a playing position in gridiron football. Linebackers are members of the defensive team, and line up three to five yards behind the line of scrimmage and the defensive linemen. They are the "middle ground" of defenders, playing closer to the line of scrimmage than the defensive backs (secondary), but farther back than the defensive linemen.
The tight end (TE) is an offensive position in American football, arena football, and Canadian football. It is a hybrid that combines the characteristics and roles of both an offensive lineman and a receiver. As part of the receiver corps, they play inside the flanks (tight), contrasted with the split end who plays outside the flanks (wide). Like offensive linemen, they are usually lined up on the offensive line and are large enough to be effective blockers. On the other hand, unlike offensive linemen, they are eligible receivers and potent weapons in a team's offensive schemes.
Arena football is a variety of eight-man indoor gridiron football. The game is played indoors on a smaller field than American or Canadian football, designed to fit in the same surface area as a standard North American ice hockey rink, resulting in a faster and higher-scoring game that can be played on the floors of indoor arenas. The sport was invented in 1981, and patented in 1987, by Jim Foster, a former executive of the National Football League and the United States Football League. The name is trademarked by Gridiron Enterprises and had a proprietary format until its patent expired in 2007.
In sports, a utility player is one who can play several positions competently. Sports in which the term is often used include association football, basketball, American football, baseball, rugby union, rugby league, softball, ice hockey, and water polo.
American football positions have slowly evolved over the history of the sport. From its origins in early rugby football to the modern game, the names and roles of various positions have changed greatly, some positions no longer exist, and others have been created to fill new roles.
A punter (P) in gridiron football is a special teams player who receives the snapped ball directly from the line of scrimmage and then punts (kicks) the football to the opposing team so as to limit any field position advantage. This generally happens on a fourth down in American football and a third down in Canadian football. Punters may also occasionally take part in fake punts in those same situations, when they throw or run the football instead of punting.
A formation in American football refers to the position players line up in before the start of a down. There are both offensive and defensive formations and there are many formations in both categories. Sometimes, formations are referred to as packages.
In sports, a starting lineup is an official list of the set of players who will participate in the event when the game begins. The players in the starting lineup are commonly referred to as starters, whereas the others are substitutes or bench players.
A platoon system in baseball or American football is a method for substituting players in groups (platoons), to keep complementary players together during playing time.
A halfback (HB) is an offensive position in American football, whose duties involve lining up in the offensive backfield and carrying the ball on most rushing plays, i.e. a running back. When the principal ball carrier lines up deep in the backfield, and especially when that player is placed behind another player (usually a blocking back), as in the I formation, that player is instead referred to as a tailback (TB).
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". Within these three separate "platoons", various positions exist depending on the jobs that the players are doing.
A fullback (FB) is a position in the offensive backfield in gridiron football and is one of the two running back positions along with the halfback. Fullbacks are typically larger than halfbacks, and, in most offensive schemes, the fullback's duties are split among power running, pass catching, and blocking for both the quarterback and the other running back.
In American football, a 4–3 defense is a defensive alignment consisting of four down linemen and three linebackers. It is called a "base defense" because it is the default defensive alignment used on "base downs". However, defenses will readily switch to other defensive alignments as circumstances change. Alternatively, some defenses use a 3–4 defense.
A kickoff specialist is a special teams position in gridiron football. They are responsible for kicking the ball in the kickoff. These players tend to have a strong leg, often capable of making touchbacks, and capable of keeping a ball in the bounds of the field of play but do not have the accuracy or technique required to be a full-time placekicker or punter. For most teams, the placekicker is the kickoff specialist.
The following terms are used in American football, both conventional and indoor. Some of these terms are also in use in Canadian football; for a list of terms unique to that code, see Glossary of Canadian football.
The one-platoon system, also known as "iron man football", is a rule-driven substitution pattern in American football whereby players played continuously on both offense and defense. Players removed for a substitute were lost to their teams for the duration of the half or quarter.
