Players in the National Football League wear uniform numbers between 1 and 99, and no two players on a team may wear the same number. Rules exist which tie a player's number to a specific range of numbers for their primary position. Additionally, rules exist which limit who may handle the ball on offense: generally players who are designated as offensive lineman, who wear numbers 50–79, are not allowed to handle the ball during a play from scrimmage, though they are allowed to do so if they report to the referee as playing out of position for a tackle-eligible play.
History
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, and numbers had little correlation with positions 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 given numbers in the 10–49 range and the offensive line numbers in the 50–89 range. 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 10–49 range, defensive line numbers ranged from 50–89, while linebackers could have just about any number. Split ends had numbers in the 80s, and many would play corner back. The AAFC of the 1940s, which would later merge with the NFL, had a different numbering system with quarterback in the 60s, fullbacks in the 70s, halfbacks in the 80s, ends in the 50s, tackles in the 40s, 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 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, which would also later merge with the NFL, used essentially the same numbering system as the NFL with some exceptions, mostly pertaining to wide receivers, who were allowed to wear numbers in the teens and 20s. The AFL's numbering system also allowed for the use of a double-zero as a number, which was used by future Hall of FamerJim 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 standardization
The NFL imposed a more rigid numbering system in 1973. When it went into effect, players who had played in the league before the 1973 season were given a grandfather clause to continue wearing their now-prohibited numbers. New England Patriotsdefensive endJulius 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. The 1973 system is still in place today, though some changes have been made periodically since then as team rosters have grown and as greater flexibility has been needed to deal with changing roster demands.
Post-1973 changes
Since 1973, only five major changes have been made. In 1979, the NFL allowed defensive linemen to wear numbers 90–99 and centers 60–79. In 1984, 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. 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. In 2015, the NFL Competition Committee allowed linebackers to wear numbers from 40–49.
The numbers used relate to the player's primary position when they are first assigned a number. If they later change positions, they can keep their prior number, unless it conflicts with the eligible receiver rule; that is, only players that change positions from an eligible position to an ineligible position are required to change numbers if they change position. A modern example of this is running backTy Montgomery, who has worn number 88 throughout his NFL career because he began his career as a wide receiver. Additionally, during a game a player may play out-of-position, but only after reporting in to the officials, who will announce to the stadium that a specific player number has reported in to alert the opposing team, other officials, and the audience that a player is legally out-of-position. A 2015 rule clarification made it illegal to use unusual formations to obscure who is and is not eligible based on uniform numbers in order to avoid having to report ineligible numbers. Some positions are not listed in the rule book, such as long snapper and special teams gunner. Teams often assign these players to a recognized position even if those players rarely, if ever, play in their official position. The rule book also allows players to appeal for exemptions to the numbering rules directly to the commissioner's office, which may grant such exceptions on occasion.
Retired numbers
Many NFL teams have retired some numbers in honor of the team's best players. Generally when a number is retired, future players for the team may not wear it. The NFL officially discourages teams from retiring numbers, as the limited number of uniform numbers available for each position can be depleted. Some teams will hold official "number retirement" ceremonies, others have "informally" retired numbers by simply not issuing them. For teams that do not retire uniform numbers, they often honor players in other ways, such as team halls of fame or the like.
Numbers 0 and 00
Numbers 0 and 00 are no longer used, though they were issued in the NFL before the number standardization in 1973. Quarterback Johnny Clement, running back Johnny Olszewski, and safety Obert Logan all wore a single-0 jersey in the NFL. Author George Plimpton famously wore 0 during a brief preseason stint at quarterback for the Detroit Lions. Jim Otto wore number "00" during most of his career with the Oakland Raiders as a play on his name, "aught-oh." Wide receiver Ken Burrough of the Houston Oilers also wore "00" during his NFL career in the 1970s. More recently, linebacker Bryan Cox wore 0 in the 2001 preseason with the New England Patriots; for the regular season, he switched to 51. Numbers from 01 to 09, with a leading "0" digit, would theoretically be allowed, but such a number has never been issued in professional football.
