History of American football positions

American Football position names are based on the role the player normally has in the offense, rather than necessarily his position at the start of the play. Tight ends, for instance, usually line up to the outside of one of the offensive tackles. However, a tight end might also line up in the area usually reserved for a wide receiver, or even take the place of a fullback in the offensive backfield; such Tight Ends are usually called H-Backs. You also might not be able to tell the difference between the halfback and the fullback by where they are lined up. Their main difference instead is based on their role in the offense (halfbacks run more, while fullbacks are usually used to block).

Offense

	TE	LT	LG	C	RG	RT		WR
WR
				QB
			HB		FB

Offensive players can be divided into three groups; the interior line, which has five members; the backfield, which has one to four members; and the receiving corps, which has two to five members. Two of the receivers must be on the ends of the line and the remainder must be in the backfield. The standard split-back formation shown above has five interior linemen (left tackle, left guard, center, right guard, right tackle), three players (exclusive of receivers) in the backfield (quarterback, halfback, and fullback), and three receivers (split end, tight end, and flanker, of which the flanker is in the backfield).

Offensive line

There are five interior linemen. From left to right they are the left tackle, the left guard, the center, the right guard, and the right tackle. In the NFL, the offensive linemen are the only players allowed to have numbers between 50 and 79. On passing plays, the offensive lineman's job is to prevent defensive players from tackling the quarterback (pass blocking). On running plays, the offensive lineman's job is to make holes in the defense that a running back can run through (run blocking). The center also initiates the play by snapping the ball to the quarterback.

Offensive backfield

The offensive backfield consists of the players who line up behind the offensive line. This is usually the quarterback and two running backs, though there can be as few as none and as many as three running backs. In the NFL, the quarterback will have a uniform number between 1 and 19, and the running backs will have numbers between 5 and 44.

The quarterback starts play by receiving the ball from the center. On a running play, he can hand the ball off to one of his running backs (or occasionally, run the ball himself). On passing plays, he can throw the ball to a wide receiver, a tight end, or a running back. Offensive linemen are ineligible to catch the ball unless they report as eligible to the officials before the play.

Running backs may be geometrically divided into halfbacks and fullbacks. Today, they are easily divided by their role in the offense. The halfback is the one who runs most often, while the fullback is usually used as a lead blocker. Of course, the fullback may run the ball occasionally as well. On passing plays, the running backs may either have a route to run, which means they are one of the eligible receivers on the play, or they may be kept back to help the offensive lineman block.

Receivers

Receivers are the players who line up to the outside of the offensive line, either on the line of scrimmage or a yard behind it. There can be anywhere from two to five of these players on the field at any time, depending on the personnel grouping being used. They are divided up into the tight ends and the wide receivers. According to NFL rules, there must be at least seven offensive players on the line of scrimmage. This affects where players line up and is the reason that tight ends and flankers often line up at the line of scrimmage.

The tight end, so named because he would traditionally line up at one end of the line, next to the offensive tackle, is somewhat of a hybrid player. On running plays, he blocks much as an offensive lineman would. But on passing plays, he is eligible to catch passes like the wide receivers are. Today, you might see a tight end lining up as a wide receiver, or in the backfield (sometimes called an H-Back). On running plays, teams will sometimes have two (or rarely even three) tight ends on the field at once (the extra tight ends taking the place of wide receivers). As such, a tight end can basically be thought of as a stronger, slower wide receiver. In the NFL, the tight end usually has a uniform number in the 80s, but it is also permitted for tight ends to wear numbers in the 40s, especially if the team carries many receivers or has retired jersey numbers in the 80s.

Although they are occasionally used in run blocking, the main job of the wide receiver is to catch passes from the quarterback. Most standard formations have two wide receivers, though other formations could have as few as none (where the two wide receivers are replaced by tight ends), or as many as five (where wide receivers take the place of the tight end and running backs). When there are two wide receivers, they usually line up the farthest away from the center. Wide receivers in the NFL were traditionally limited to numbers in the 80s, but recently they have also been allowed numbers from 10 - 19.

The terminology of the wide receivers varies. With two wide receivers, they will often be called the flanker and the split end. The split end lines up on the side opposite the tight end, and the flanker lines up on the same side as the tight end, behind the line of scrimmage. This gives the flanker an advantage because he has more open space with which to avoid the defender. When there is a third wide receiver, as often occurs in Canadian football or in NFL and college football offensive formations in which an additional downfield receiver is required, he is often called the slot receiver or slotback, because of his location between one of the other wide receivers and the lineman. Other names for these positions are the "X receiver" for the split end, the "Y receiver" for the tight end and the "Z receiver" for the flanker.

Defense

		DE	DT		DT	DE
			LB	LB	LB
CB		FS				SS		CB

As with the offense, the defense has 11 players. They can be divided into the Defensive Line, the Linebackers, and the Secondary. How many there are of each will depend upon a team's formation, as well as the personnel groupings the opposing offense brings onto the field. The most common defense in the NFL, though, is the 4-3 (pictured above). In the 4-3, there are 4 defensive lineman (Left Defensive End, Left Defensive Tackle, Right Defensive Tackle, Right Defensive End), 3 linebackers (the Strong-Side Linebacker, the Middle Linebacker, and the Weak-Side Linebacker), and 4 players in the Secondary (Left Cornerback, Free Safety, Strong Safety, and Right Cornerback). In another popular formation, the 3-4, a team has 3 defensive lineman and 4 linebackers:

			DE	DT	DE
		LB	LB		LB	LB
CB		FS				SS		CB

Defensive line

The Defensive Lineman are the first line of defense. Their job is to disrupt the play in any way possible and prevent the offense from gaining yardage, whether by tackling a running back, sacking the Quarterback, or blocking a pass or kick. The 4 defensive linemen usually line up between the 5 offensive linemen. So together, they might look like this:

  DE  DT   DT  DE
--------------------LINE OF SCRIMMAGE
OT  OG   C   OG  OT

In the NFL, Defensive Lineman may wear numbers in the 50s - 70s and 90s.

               FS
                    SS
              LB  LB  LB
   CB        DE DT DT DE         CB
--------------------------------------LINE OF SCRIMMAGE
  WR        OT OG C OG OT  TE     WR
                  QB
                TB   FB

Linebackers

In a 4-3, there are 3 linebackers. They line up behind the defensive line. The linebacker who lines up on the same side as the tight end is called the Strong-Side Linebacker (nicknamed Sam), while the one on the end opposite the Tight End is the Weak-Side Linebacker (nicknamed Will). The Linebacker in between them is the Middle Linebacker (nicknamed Mike).^[1] In the passing game, the Sam Linebacker will usually cover the Tight End, while the Will and Mike linebackers will rush the quarterback and cover any running backs that run patterns. In the rushing game, they have to help the defensive line tackle the running back. In the NFL, Linebackers wear numbers in the 50s to 90s.

Special teams

There are several specialized positions that exist on special teams.

• Kicker – The kicker attempts kickoffs as well as field goals and extra points. Occasionally, these roles will be separated (due to a field goal kicker who doesn't have a very strong leg, for example) into the roles of Field Goal Kicker and Kickoff Specialist.
• Punter – The Punter has two major jobs. More often than not, the punter tries to kick the ball as far down the field as he can, where the other team will take possession. However, when the offense has an advanced field position, the punter can attempt to "coffin corner" a punt, kicking the football so that the receiving team starts their possession with poor field position. Sometimes the Punter will also be the Kickoff Specialist. In the NFL, kickers and punters are assigned uniform numbers between 1 and 19 (as are quarterbacks).
• Long Snapper – The Long Snapper takes the place of the center on field goal kicks and punts. His job is to accurately snap the ball backwards to either the punter or the holder, so that they can quickly do their job. The long snapper is usually listed as a Tight End or a Linebacker on rosters.
• Return Specialist – The Return Specialist is the player who is back deep to return punts and kickoffs. There is usually one returner for punts, and two returners for kicks. Some return specialists only do one or the other, while others are good at both roles. Return specialists usually double as Wide Receivers or Cornerbacks.
• Gunner – The Gunner is a special position on Punts and Kickoffs. See link for more information.

History

Origins in rugby

See also: Rugby union positions

Being variants of 19th Century rugby football,^[2] American and Canadian football position nomenclature has its origin there. Early rugby did no more than distinguish in tactics between the great bulk of the players who played as forwards and the relative few who played back defensively as "tends", as in goaltenders. After a while, the attacking or at least counterattacking possibilities of playing close behind the scrimmage (which later came to be called "scrummage") came to be recognized, and some players stationed themselves between the forwards and tends as "half-tends". It being seen that the players outside scrimmage (the "pack", i.e. the forwards) were not limited to a defensive role, the tends and half-tends were renamed "back" and "half back" positions.

As the game became more sophisticated, backs positioned at different depths (i.e. distances behind the forwards) were further differentiated into half back, three quarters (the fraction 3/4) back, and full back, according to English and Scottish nomenclature, or quarter back, half back, and full back in the Irish nomenclature. In rugby the English-Scottish nomenclature was eventually adopted worldwide, with the word, 'back," often omitted for brevity from the half back ("half") and three quarters back ("three quarter") names, and "fullback" as a single word.

In some systems, "five-eighths back" has been added. (The illustration here, of singular forms, should not be construed as indicating the number of players in any of those positions, nor is the fraction in the name at all proportional to the actual depth of the position; they indicate only a quirky form of ordinal number, not cardinality.) Having the backs at different depths facilitates passing movements in which the ball is tossed from one player to (usually) the next closest, such that each back receiving the ball in turn can be running forward and yet not ahead of the player who threw it, forward passing of the ball being illegal. Because of the involvement of the 3/4 backs, such a movement is often called a three-quarters movement.

It was the Irish nomenclature of quarter back, half back, and full back that came to North America for use in what was to become the dominant native form of football. The terms became hyphenated and eventually unhyphenated single words, "quarterback" (QB), "halfback" (HB), and "fullback" (FB). The lack of quarterback in the English-Scottish nomenclature for rugby led to the position name "scrum-half" to distinguish the halfback playing close to scrimmage (renamed "scrummage" or "scrum") from another who would "stand off" from it or "fly" away — the "stand-off" or "fly-half".

Early Canadian football

Around 1900, at the same time, the number of players on a Canadian football team was reduced to 14, the number of players in scrimmage (formerly packing all the forwards) was fixed at 3 per team. It became customary for 6 to 8 of the other players to continue as what might be known in rugby as loose (non-packing, i.e. not binding together) forwards who in Canadian football formed "wing lines" on either side of the scrimmage. In scrimmage, each team had one centre scrimmager flanked by two side scrimmagers. The side scrimmagers bound with hands and arms to their centre scrimmager. The centre scrimmager of the side entitled (and required) to do so would put the ball down in front of him for play by scrimmage, while both sets of three bodies each ("formed into one compact body" as the rules specified) were crouched and shoving forward at each other, probably meeting at the shoulders as do the front row of forwards in rugby's set scummage. Depending on the rules, details of the time for the particular circuit of Canadian football clubs, the centre scrimmagers would either contend with their feet for the ball, or one would be entitled to foot it first (usually heeling it back), while the other team's would try to spoil the ball's delivery.

The backfield of 3 to 5 players continued to use the nomenclature (see above) of quarterback, halfback, and fullback, and sometimes included one or two flying wings (see below).

When 6 played on the winglines, their positions were called "inside wing", "middle wing", and "outside wing", arrayed in order away from the scrimmage. An additional player called "flying wing" could "fly", between a position on the wingline outside the outside wing, and the backfield.

However, the 14-a-side game's rules never required certain numbers of players in either the winglines or the backfield.

With the later reduction in sides from 14 to 12 players, and introduction of the thrown (not footed) snap, the positions of the three scrimmagers were replaced by a single position called "snap". The position names in the winglines were retained for a while, but eventually replaced by the USA nomenclature, although it wasn't until the 1960s, that Canadian rules required 7 players on the offensive line, unless they were playing short handed. Before that, only 5 were required on plays in which no forward pass was thrown, so it's likely that in such situations, one or both ends were replaced by or became a back. "Snap" became "center" and considered a wingline or line position. "Centre" even became the rule book designation of the snapper, although as in the USA version, there is no necessity that the player who snaps the ball have equal numbers of teammates flanking him or her on the line.

More position names

A tendency was seen, from early on, for players to keep their position names even when playing out of that position. For instance, before the minimum number of players on the offensive line was fixed at 7, when players who would otherwise be in the line as guards or tackles played from offensive backfield positions, the formation was known as a "guard(s) back" or "tackle(s) back" formation.

Meanwhile, another position name was introduced. Players were placed in the offensive backfield just outside of their ends, in a position that came to be called "wingback" (WB). Formations with one or two wingbacks came to be called single or double wingback or wing formations.

Over time, the typically fast back who played fullback, on offense and defense, was replaced by a heavier one who presented a greater threat to run with the ball more or less straight ahead, and to tackle his opponent trying to do the same. For this purpose, the player tended to be placed closer to the line than previously — often as far forward as the halfbacks (the offensive backs then forming a letter T, sometimes called a "straight T," later to distinguish it from slight variants wherein other backs didn't form a line perpendicular to that from the quarterback) or even farther forward. But the position kept being called "fullback". On defense, this necessitated another position name for the fast back who played farthest back: "safety man" or simply "safety" (S), representing the last defense against a breakaway play, and the position from which to field opposing kicks. Approximately, on defense, the quarterback and fullback exchanged positions from what they'd been playing on offense, and the quarterback became the safety.

Still, when at the beginning of the 20th Century, a penalty was introduced for hitting the opposing kicker after a kick, the foul was at first called "running into the fullback", inasmuch as the deepest back usually did the kicking.

Confusion increased when the legalization of the forward pass made it more advisable for teams to defend with fewer on the line of scrimmage and more behind. Although the offense could no longer play "guard back", for instance, the defense had no such limitations. A common defensive formation was the 6-2-3 or 6-2-2-1, shown below arrayed against an offense's straight T:

S HB HB
C FB
____E_ T__ _G ____G_ T _ E____
E T G C G T E
QB HB FB HB

Note that the so-called center and fullback are playing left and right versions of the same position. The positions were later renamed "linebacker". However, that did not become the usual way to name that position until platoon football became common, with players specializing in offense or defense, substituted according to which team has the ball. There seems to have been some tendency for defensive positions to be named for where the player would play on offense, although quarterback and safety formed an early exception.

When linebackers are playing close to or level with the line, a somewhat reliable way to distinguish them from line players is that the defensive line players will be in a 3- or 4-point stance, meaning that they will be supported by one or both hands, in addition to feet on the ground, while the linebackers will have only feet on the ground. Line players with one or both hands on the ground are called "down linemen"; typically all defensive linemen are so positioned.

Alternate position naming schemes for an offensive formation are illustrated below in a version of single wing formation:

E     G   C   G   T   T   E
                QB

HB HB
FB E T C G G T E
QB FB WB
TB

In the top illustration the center is flanked by guards in the 4-2 unbalanced line (4 players on one side, the "strong side" of the center, 2 on the other, "weak", side) as in a balanced line, leaving the tackles together. In the bottom illustration, the guards are kept "inside" by being next to each other. The end positions are fixed by rule, because "end" is a rule book term.

As to the backfield, the top illustration preserves the principle of the names, reflecting distance from the line. However, the bottom illustration needs further explanation, having eliminated the halfbacks and introduced a new position name, "tailback" (TB). Wingback has been described above, but the "WB" in the above illustration is deeper back than that position name would seem to warrant. That's because this is a "wingback deep" version of the single wing, and the position is named wingback because the player is named for his true wingback position as it exists in other versions. In this version the player may stand as deep as any other back, but there has been a reluctance to identify formations in American football as having more than one fullback (or tailback — see below), although two-fullback systems were not uncommon at one time in rugby.

What to make of the replacement of the other halfback from the top illustration by the fullback in the bottom one? Well, if the wingback were playing in a true wingback position but named halfback, then the other "halfback" would be playing deeper and thus deserve the name fullback. Another justification is that the player positioned as the left halfback in the top illustration tends to have the fullback characteristics described above. But rather than call the faster, lighter back behind (and in this formation, to the left of) him a halfback and so contradict the distance-back-determines-the-name principle (and rather than add rugby's three-quarters back), we call that player "tailback" — the tail of the formation, farther back than the fullback. Even when two players positioned to take a thrown snap in a single wing formation are level with each other (i.e. at equal depth), the faster one (usually playing weak side) is often called the tailback and the more massive one the fullback.

Note that the quarterback in this formation is not in position to receive the snap. ASCII art (letter diagrams) cannot show this fine a detail, but a quarterback in position to take a handed snap is allowed by rule to stand farther forward, in a place which would otherwise cause illegal confusion as to whether the player was in the backfield or the line. However, the popularity of thrown-snap formations from about 1920 to about 1950 (and the illegality of the handed snap in Canadian football when snapping by hand rather than foot was first prescribed in that game) induced some teams to place the quarterback a little farther back, receiving the snap via a short toss.

Even ASCII art is subtle enough to show the left end above a little farther from the nearest other line player of the same team than is the right end. Such a slight additional gap is said to be "flexing" that end, but does not produce an additional position name. However, when the gap is considerably greater, that is said to be a "split end" (SE). That produced a position name when on offense a team played with one end split and the other not split — a "tight end" (TE). The split end being specialized for going downfield to catch forward passes, it becomes more useful to differentiate the split from the tight end than between left and right end.

Instead of wingbacks or conventionally-placed halfbacks, an offensive team could have backs positioned wide of the rest of the formation, similarly to a split end, to be pass receivers. Such a back would be called a "flankerback" or "flanker" (FL).

A more straightforward use of the position name, "tailback," is shown below in an offensive short punt formation, whose use, despite its name, is not confined to punting. Without rugby's three-quarter backs, the sequence of quarter-, half-, full-, and tailback makes do. The line shown is balanced with one split end. In such a case, the side with the tight end is sometimes said to be the strong side of the line, and hence of the formation, because the tight end is better placed than the split end to block, especially on running plays. An additional justification for calling that the strong side in the example below is that the backfield has more players on that side, although that will not always be the case, and in this case the positioning of backs does not produce strikingly strong and weak sides, as opposed to the single wing formation shown above.

SE                     T  G  C  G  T  TE
                                QB
                         HB
                                FB
                             TB

If the deepest back were a specialist in punting, one might substitute "P" for "punter" for the "TB" above.

Age of confusion

The trend of naming offensive positions for the role or build of player in it continued. In some cases, this obfuscates important details. A recent diagram of a short punt formation for offense in youth football had no quarterback, but two fullbacks at the depth of the QB shown above, and a halfback at the position labeled FB above. Some discussions of the single wing previously diagrammed claim it has no quarterback. And many's the time when a player in the farthest back position, in a formation similar to the short punt shown above, is referred to as quarterback! Position names no longer needed to reflect any given player's combined roles on offense and defense when few played both ways. As a result, position naming on defense has become less confusing and more informative. However, position naming on offense, while tending to eliminate obsolete distinctions, has also tended to hide important ones and confuse others.

Offenses and defenses continued to adapt to the increases in forward passing favored by the rules. Below is diagrammed a 3-4-4 (or simply "3-4") defensive formation and an offensive formation it might line up against across the lines of scrimmage, as popular beginning in later portions of the 20th Century:

                    FS          SS

CB CB
OLB ILB ILB OLB
__________________E_______NT______E___________________
WR T G C G T TE
QB WR RB RB

Beginning with the defensive line, one notices a slight departure from previous nomenclature with the position labeled "NT". Why not simply "T"? The superfluous designator "middle" when the defense was playing with an odd number on the line less than 7, as in "middle guard", was discussed above. (This invites the unanswered question of whether, if the defense has an 8-player line, it includes a "left center" and "right center".) "NT" stands for "nose tackle", "nose" having been introduced with guards to indicate a position "on the nose" of the opposing center, although "nose guard" had not been a popular term, probably because it suggested a piece of protective equipment. There is justification for the extra word, in that the tackle in a 3-player defensive line could well play off center; however, this distinction is not maintained with teams using such a tactic, so the position could and probably should be referred to simply as "tackle" — or "defensive tackle" (DT) in a player roster (see below).

The linebacker (LB) positions are straightforwardly distinguished as inside (ILB) and outside (OLB). When there are only three linebackers, the one inside is labeled middle linebacker (MLB), and the outside positions can instead be named as left and right. The defense's halfbacks have been renamed cornerbacks (CB), a fitting term given that they play at the edges or "corners". The term has no spurious indicator of the depth as which they are positioned in the defensive backfield.

Finally there are shown two safeties. In this case they are distinguished as "free safety" (FS) — also known as "weak safety" — and "strong safety" (SS). The strong safety is on the side following the strong (tight end) side of the balanced offensive line (see above), and has responsibility for covering (guarding as a pass receiver) the TE, while the free safety has no such coverage assignment. However, the coverage played by defense does not always easily allow assignment of such distinct names for safeties. A formation with more than 2 safeties could have them described by their relative geometric placement—outside, shallow, deep, etc.-but such is not general practice; however, see the discussion of the "nickel" below.

The offense is diagrammed in what was for some time referred to as a "pro set"-- "set" indicating that the players are stationary, although one back may go in motion from it. This particular version is said to have a "deuce", "flank" backfield. From the description above of the straight T, this formation can be seen to be derived by splitting one end and moving the halfback on the opposite side to a flanker position. Instead of "SE" and "FL" for those positions, however, we see "WR", for "wide receiver".

In the 1960s, teams would distinguish between flankers (e.g. the New York Jets professional football club's George Sauer) and split ends (e.g. his teammate, Don Maynard) on their player rosters. For a relatively brief period, game rules had been adopted in some codes, requiring different uniform numbers for line players from those of backs, and the position naming distinction carried on for a while after the rules were amended to require only certains sets of numbers for ineligible and eligible receivers of forward passes. It became commonplace for ends to shift into backfield positions and vice versa. By the 1970s, the common practice changed to refer to flankers and split ends both as wide receivers or, more colloquially, "wideouts" — they play from wide of the rest of the formation.

Note, however, that the playing rules still distinguish between ends and backs on offense. There are differences as to the motions, the players in those positions are allowed to make, during and preparatory to their team's snapping the ball. At the time they snap the ball, the team is required to have 7 players (minus any number their side is playing short in Canadian football) on their line of scrimmage, which includes split or tight ends, but not flankers or wingbacks.

Meanwhile, the distinction between fullback and halfback was erased, each replaced by "running back" (RB). That term became popular during the 1960s as well, although even into the 1970s, some playing the pro set kept the HB-FB distinction. So, for instance, in the flank formation shown above, those positions were named as in the straight T, while in the "split" version of the deuce backfield, the fullback occupied the other halfback position shown in the straight T. The distinction referred to the build of the players, the fullback being a stronger runner more or less straight ahead, and the halfback faster to attack the defense's flanks. However, on many teams there was no strong distinction between those backs, and since their major role was running with the ball, "running back" was most descriptive without maintaining a spurious geometric connotation that'd become outmoded by their lining up in different depth relationships.

Alternative names for RBs are "deep backs" and "setbacks", although the latter is disfavored because it has also been used for backs in general, both on offense and defense. There is, moreover, a generic term for the deeper-playing backs (CB & S) on defense: "defensive back" (DB), appropriately enough. Note that the term excludes the linebackers, even though they be backs in the traditional sense because they are usually not on their team's line of scrimmage. There also exist the generic terms "defensive lineman" (DL) and "offensive lineman" (OL), although the latter refers only to the interior linemen, excluding the ends because of their eligibility to receive forward passes.

However, to this day many teams maintain the offense's fullback-halfback distinction, especially in "full house" backfields, i.e. those with a quarterback and 3 running backs, that is, no backs playing wider as wingbacks or flankers. This is confusing enough, when the fullback plays slightly forward of the halfbacks, as in the Y formation shown below, later used to run the wishbone system (the backs forming a letter Y or a resemblance to a wishbone):

E         T  G  C  G  T           E
                QB

FB
HB HB

At least, that one is an easy enough derivation to visualize from the original diamond, with the depth of the fullback inverted with respect to the halves. However, some formations have placed the heavy back even more starkly forward, to function as a blocker for the running backs. In the diagram below of the V formation used by Dartmouth College in the 1950s, the respective position names have been rationalized as "BB" (a not-very-popular designation, "blocking back") and RB:

E  T  G  C  G  T  E
         QB  BB

RB RB

(The running and blocking backs can be seen to form a letter V.) However, in its time the running backs were known as halfbacks and the blocking back as fullback. Another such example is the I formation, shown below in a with-wingback version:

WR                T  G  C  G  T  TE
               WB       QB

FB TB

The diagram shows the more geometrically rational designation of tailback behind the fullback. However, some would label the deepest back in this form of deuce backfield "HB", considering one halfback to have moved behind the fullback, who is in both the role of blocking back and the heavy up-the-middle runner. Those who would emphasize the blocking role of the FB (the "up back") might even label the deepest back, "RB", with a BB instead of FB. Few, however, would use the straightforwardly geometric labels of QB, HB, and FB in that order from front to back.

Note also that the wingback is on the wing of a tackle rather than an end. This is accepted nomenclature where an end is split ("WR" above). The wingback is just behind and outside of the "interior lineman" (line player other than end). However, it is not uncommon for a wingback to be outside the tight end in an I or other formation where the opposite end is split.

In the power I formation, instead of the wingback shown above, there is another deep back in the traditional halfback position. That position in the power I is probably called "halfback" more than any other name. In the triple I, where all the backs are in one line perpendicular to the lines of scrimmage, one could hope for the backs to be called quarter-, half-, full-, and tailback in order of depth, but various names are probably used.

The diagram below of an "ace" formation deliberately mixes terms/symbols for wide receivers:

E              T  G  C  G  T                WR
      SB             QB            WR

RB

On the left are represented the more traditional and descriptive terms "end" and "slotback" (SB). The latter is for a position that would be labeled "FL", except that the back is in a "slot" between tackle and end (instead of outside of the end), here illustrating a double "wide slot" formation. (It's wide because the end is fully split, rather than merely flexed — see above.) There being no tight end, there seems to be no need to label either end as split; both are. But on the right, the slotback and end positions are merely labeled as wide receivers. Note that the single running back here is shown to one side of the center-quarterback combination, but that "ace" RB could as well be directly behind them.

In some cases, the specific terminology of certain coaches has made its way into the general parlance. Coaches, having no motivation to publicize their plans, usually adopt cryptic codes for certain positions, using letters, numbers, or short names for their convenience. One set of designations which has been making the rounds, as of this writing on Web sites, purporting to explain football is the letters X, Y, and Z to designate receivers. It is doubtful that many coaches agree on the use of these terms to designate specific positions consistently from play to play, and those letters don't seem to enlighten but only to obscure. (One manual for football spectators, in the 1960s, explained that someone calling offensive plays in the huddle would point to primary, secondary, and tertiary receivers while giving them those letters; those designations would vary depending on the play, not on the positions those receivers occupied.) However, one such letter designation has caught on recently: "H-back", illustrated in the offensive formation below:

E            T  G  C  G  T              E
                   QB      WB

HB RB

Here the H-back is represented by the symbol, appropriately enough, "HB". The H-back position is like that of the "wingback deep" position previously described in a version of the single wing formation, and here is shown behind a wingback to emphasize that, although more often the H-back and wingback, if there is one, are on opposite sides of the set. You may say the abbreviation "HB" is already taken up by the halfback. The H-back does occupy a position about the same as the halfback in the diamond formation of the 19th Century. It is likely that "H-back" is a term derived by back formation (pun unavoidable) from the abbreviation for halfback, although arbitrary letter designation by some coach is just as good an explanation.

You may see an offensive formation like that below, described as one of 3 tight ends:

E  T  G  C  G  T  E
         QB          WB

RB RB

However, it is labeled above as a version of the wing T, i.e. a T formation wherein one deep back has been replaced by a wingback. The description of its having 3 tight ends is absurd, inasmuch as a line can have only 2 ends, but comes about when the wingback position is occupied by a player most suited to blocking who otherwise usually plays tight end. If the extra blocker up front is actually in a line position, then, considering that a potential eligible receiver is being sacrificed, it would be better to conceive the formation as having an extra tackle or guard:

E  T  G  C  G  T  T  E
         QB

RB
RB

In the same vein as a formation's supposedly having 3 tight ends, examine the shotgun formation below. This is similar to the short punt formation shown previously, except that potential forward pass receivers are more widely spread. It is therefore, like the double wide slot offensive formation shown previously, a type of spread formation:

WR                  T  G  C  G  T             WR
                WB                 WB                      WR

TB

However, many would label the tailback above as quarterback, even though the position is clearly the deepest back! Until 1960, the formation above would have been called a double wing, and the tailback labeled a fullback, there being no need for the tailback designation when the backs assume so few intermediate depths. However, the deep back position above is usually occupied by a player who habitually plays QB, so the habitual position name tends to stick, as with the "extra tight end".

The identification engendered by the T formation of quarterback as someone who takes the snap is so strong nowadays that some describe the single wing formation diagrammed previously (under "more position names"), wherein the quarterback is positioned behind other interior line players than the center (and therefore cannot conveniently receive the snap), as having no quarterback! Such descriptions may have the QB as BB, although the system used may involve that player considerably as a ballcarrier or receiver, not just a blocker.

On defense meanwhile, an opposite philosophy to position naming is sometimes followed from that of the supposed third offensive end. Instead of the position name following the player to a different position, a new position name may be applied in such a substitution situation. This occurs when a team that usually uses 4 defensive backs (counting cornerbacks and safeties) adds a 5th, thus producing the "nickel" defense (a nickel being a 5 cent piece). It will be said that the extra DB is the "nickel back", even though coverage assignments will be redistributed, and therefore no particular DB is functionally or positionally in a "nickel" position, distinct from the other 4. Nor, if a 6th DB is added, could one distinguish between the "nickel" and the "dime" back. However, if they are subbed in one at a time, an observer may apply "seniority" in naming one "nickel", etc. A roster will usually simply list such players as S, CB, or simply DB.

Making sense of it all

The trend away from geometric naming of the offensive positions has led to considerable confusion. It has been said that some coaches at low levels of football, having heard game descriptions that included a team's having "put their tight end in motion", have done exactly so, and incurred the penalty for the resulting illegal motion. Because of the rules of the game, it frequently matters whether a player of the offense is on the line of scrimmage or in the backfield, and in those cases the descriptor "wide receiver" is insufficient and "end in motion" (except in Canadian football, where they're allowed to be shuffling sideways along the line of scrimmage when the ball is snapped) is nonsense, although it may reflect the way the player in question is listed on the roster. In describing the play in a National Football League game, one may hear the contorted locution, "The quarterback was eligible to receive a forward pass because he was in the shotgun formation", when it would be far simpler to say that the team's eligible receivers included the tailback who took the snap; the rules apply differently depending on whether the player is positioned behind the snapper to take a handed snap, or further back and hence in the backfield.

One can delineate two types of useful nomenclature. One type is for such purposes as calling play-by-play on radio, in text, or as described to a blind person. Such a nomenclature focuses on where a player is when the teams line up for scrimmage, and can describe the formation overall. Such nomenclature is also useful for technical purposes — instructions for coaches, for example. In this type of nomenclature geometry predominates, and there are no paradoxes such as extra ends, ends in motion, or quarterbacks standing deep in the backfield. For many play-by-play purposes, some geometric details, such as whether a wide receiver is an end or a flanker, can be glossed over unless they come into play. If a wide receiver is described as being in motion, the announcer, in calling it "motion," conveys it as legal play by a flanker, but if an end changes position, the announcer refers to the player as "shifting" instead. The advantage of speed in calling a game is manifest, and it's faster to say "Jones and Smith are split out wide left and right" than to specify that one is a split end and the other a flanker, or that both are flankers or ends.

The other type of nomenclature describes players by their usual roles — a description that's more suitable in describing a whole game or season than play by play. Such nomenclature may be used on rosters or in scouting reports, for instance. While in 1950, it would've been common to say, "This team needs a passer", to include various positions from which a player might throw forward passes (and a pro team might well have converted a college tailback into a quarterback), it doesn't seem to do much harm to say, "This team needs a quarterback", in an era when one associates quarterbacks with passing and vice versa. On the other hand, it doesn't hurt at all to mention the skill, rather than the position, if it's really a skill that's sought rather than a "job title". And if a team's standard formation is shotgun, nothing is gained by including "quarterback" in the roster if there really isn't one.

In describing defenses, there doesn't seem to be a need for dual nomenclature. Nobody sees a need to geometrically break down a formation of 3 safeties into strong [side], weak [side], and "middle", for instance, although if a team is expecting a kick one might well specify positions of "deep safety" and "shallow safety". The line and linebacker position names give role and geometric information about equally. In odd-man line formations, the adjective "nose" can be reserved to distinguish cases wherein the middle lineman is directly opposite the snapper from those where the middle defensive line player is offset, and "middle" is superfluous if the existence of the odd number of linemen has already been conveyed.

References

1. ^ Understanding the Defensive Positions in Football
2. ^ Football: The Rugby Union Game, 1892, Frank Marshall, ed., pp.18-22

External links

• NFL.com's Pat Kirwan discusses the different personnel groupings that NFL Teams use

Positions in American football and Canadian football
Offense			Defense			Special teams
Linemen	Guard, Tackle, Center		Linemen	Tackle, End, Nose tackle		Kicking players	Placekicker, Punter, Kickoff specialist
Quarterback			Linebackers			Snapping	Long snapper, Holder
Backs	Halfback (Tailback), Fullback, H-back		Backs	Cornerback, Safety		Returning	Punt returner, Kick returner
Receivers	Wide receiver, Tight end, Slotback			Nickelback, Dimeback		Tackling	Gunner
Formations – Nomenclature