National Football League uniform numbers

Prior to 1973

The earliest numbering systems were significantly different from the modern variation. Until the 1920s, when the NFL limited its rosters to 22 players, it was rare to see player numbers much higher than 25 (Red Grange was a notable exception, wearing 77 with the Chicago Bears while playing halfback, which would not be allowed under current NFL rules), and numbers had little correlation with positions (in 1929, the Orange Tornadoes subverted the system even further, experimenting with using letters instead of numbers.^[1])

The numbering system used today originated in football's past when all teams employed some variation of the single wing formation on offense. When teams switched to the T-formation in the 1930s and 1940s, the numbers were taken with them to whatever position evolved from the old single wing position. This numbering system originated in college football and was used only informally in the NFL until 1952; the backs were numbered 1–4 and the line 5–8. Tailbacks, left halfbacks or flankers (1-back), like Frank Gifford, were given 10s. The blocking back (2-back), which evolved into the quarterback in the T formation, had a number in the 20s (e.g. Bobby Layne and John Hadl, and Doug Flutie during his college career). Fullbacks (or 3-backs) were given numbers in the 30s, and right halfbacks, what would become simply the halfback or running back (4-backs) in the 40s, centers in the 50s, guards in the 60s, tackles in the 70s, and ends in the 80s. Earlier, defensive players wore numbers that reflected their offensive position, as many players played both offense and defense. For example, quarterbacks and halfbacks usually played in the defensive back field and so had numbers in the 10s, 20s, and 40s. Fullbacks were linebackers and had numbers in the 30s; centers and guards were linebackers as well and has numbers in the 50s and 60s respectively. Guards and tackles played the defensive guard and tackle positions and had numbers in the 60s and 70s respectively. Ends had numbers in the 80s. Split ends (e.g. Emlen Tunnell) would be cornerbacks and tight ends (e.g. Fred Dryer, Buck Buchanan) would be defensive ends but all would have numbers in the 80s. The league allowed Johnny Olszewski to wear the number zero (0) during his career.

The CFL had a different numbering system with the ends in the 70s, making wide receivers up until recent times having 70s numbers (CFL Receivers may still wear numbers in the 70s, but as most receivers are from the U.S., they will usually wear 80s if they choose to wear a higher number; CFL receivers may also wear numbers from 1–19). Likewise, centers were usually assigned numbers in the 40s; in modern times, the CFL has required offensive linemen to wear numbers between 50 and 69.

The AAFC had a different numbering system with quarterback in the 60s (Otto Graham), fullbacks in the 70s (Marion Motley), halfbacks in the 80s, ends in the 50s (Mac Speedie), tackles in the 40s (Lou Groza), guards in the 30s, and centers in the 20s. When the AAFC merged with the NFL in 1950, the AAFC players kept their old uniform numbers which caused confusion and resulted in the NFL going to a standard numbering system in 1952. This resulted in many star players having to change their numbers in mid-career. Examples are Otto Graham going from 60 to 14, Norm Van Brocklin going from 25 to 11, and Tom Fears going from 55 to 80.

The American Football League of the 1960s mostly used the same numbering system as the NFL did, with some exceptions, mostly pertaining to wide receivers, who were allowed to wear numbers in the teens and 20s (as the AFL had a greater priority toward offense, the league often made use of flankers, receivers positioned in the backfield). The AFL's numbering system also allowed for the use of a double-zero as a number, which was used by future Hall of Famer Jim Otto, center for the Oakland Raiders; after wearing the number 50 in his rookie season, switched to 00 which he wore for the remainder of his career.

1973 standardisation

The NFL imposed a more rigid numbering system in 1973. When it went into effect, players who played in the league before then were given a grandfather clause to continue wearing newly prohibited numbers (i.e. Otto and Burrough were allowed to keep their 00 jerseys, many wide receivers wore jersey numbers in the teens and 20s before the rule changes required receivers to wear numbers in the 80s, and many defensive linemen and linebackers wore numbers in the 80s). New England Patriots defensive end Julius Adams was the last player to be covered by the clause, wearing number 85 through the 1985 season, but he had to wear number 69 when he briefly came out of retirement in 1987 during the 1987 strike. This was in stark contrast to when the league required linemen to wear jersey numbers in the 50–79 range in 1952 (for ineligible receiver purposes), since Cleveland Browns quarterback Otto Graham wore number 60 prior to this change. Graham switched to number 14, which was retired by the Browns while his more familiar number 60 remains in circulation today, most recently worn by guard Ryan Miller in 2012.

Post-1973 changes

Since 1973, only five major changes have been made. In 1979, the NFL allowed defensive linemen to wear numbers 90 to 99 and centers 60-79. In 1984 ^[2], the NFL allowed linebackers to wear jersey numbers in the 90–99 range, since more teams were making use of the 3–4 defense and thus were quickly exhausting numbers for linebackers, who previously were only allowed to wear numbers in the 50–59 range. (Before these changes, the NFL had outlawed the 90–99 range for regular season use, since it was rarely issued before 1973, but did permit it for the preseason; Lawrence Taylor wore his college number 98 during his rookie training camp with the Giants in 1981 before switching to his more familiar 56 before the start of the season.) Another change occurred in 2004, when the NFL allowed wide receivers to wear numbers 10–19 in addition to the 80–89 range; this was due to several NFL teams retiring 80-range numbers, as well as teams employing more receivers and tight ends in their offense. Since 2010, defensive linemen are allowed to wear numbers 50-59; this is in part because of the interchangeability of linebackers and defensive ends (a defensive end in a 4-3 defense would be an outside linebacker in a 3-4). In 2015, the NFL Competition Committee approved linebackers using numbers from 40 to 49.^[3]

Exceptions

Many exceptions to the rules have been granted. Usually, this was done for a few reasons. First, players who had a legal number under a prior set of rules were allowed to keep the number (this happened to many players after the 1973 numbering conventions were established). Second, players may have played one position early in their career, but switched to a new position and retained their old number. Third, a team may exhaust the available numbers for one position, and thus have no choice but to assign a different number to a player. This was more frequent prior to the 21st century when numbering rules were more strict; for example until 2004 both wide receivers and tight ends were required to be between 80-89 and under modern offenses, it is likely that teams would have more than 10 such players. The addition of the 10-19 range for wide receivers and the 40-49 range for tight ends has reduced these problems. There are some positions, such as long snapper and gunner which are not covered at all by the official numbering conventions, players in those positions are given a wide range of numbers, and may even be "officially" listed as a position such as "wide receiver" or "tight end", even if they rarely if ever play those positions in game situations.

During the preseason, numbers outside permitted ranges (usually single digits) may be worn if there are no numbers available within the range for certain positions, usually wide receivers or backs.^[5][6][7]