Retired number
Retiring the number of an athlete is an honor a team bestows upon a player, usually after the player has left the team, retires from the sport, or dies, by taking the number formerly worn on their uniform out of circulation. Once a number is retired, no future player from the team may wear it, unless the original player permits it; however, in many cases the number cannot be used at all. Such an honor may also be bestowed on players who had highly memorable careers, died prematurely under tragic circumstances, or have had their promising careers ended by serious injury. Some sports that retire team numbers include baseball, cricket, ice hockey, basketball, American football, and association football. Retired numbers are often referred to as "hanging from the rafters" as they are so displayed in the team's home venue, either emblazoned on jerseys with the players' names or made into appropriately colored/styled banners.
The first number officially retired by a team in a professional sport was that of ice hockey player Ace Bailey, whose number 6 was retired by the Toronto Maple Leafs in 1934.
Some teams in sports with eleven players per side have retired number 12 in honor of their fans, or the "twelfth man". Similarly, the Sacramento Kings and Orlando Magic retired number 6 in honor of their fans, the "sixth man". A team may decide to retire a number in honor of tragedies involving the team's city or state. For example, the number 58 was retired in 2018 by the Vegas Golden Knights hockey team in honor of the 58 victims killed in the 2017 Las Vegas shooting.
North American sports leagues
If a jersey is retired and an active player is still wearing it, the player is usually permitted to wear the number for the remainder of their playing career with that team. If the player later becomes a coach or manager for the same team, and if the sport is one in which coaches and managers wear uniform numbers, then the player may wear the retired number for the duration of their career with the team in this capacity.However, in some cases, the player may still elect to change their number. For instance, in 1987 the Boston Bruins of the National Hockey League decided to retire jersey number 7 in honor of Phil Esposito, who had become a star while playing for the team. At the time #7 belonged to Ray Bourque, who was the Bruins' captain and had become a star in his own right. On the night of the ceremony honoring Esposito, Bourque took to the ice wearing his normal #7 jersey, which he had worn since breaking into the league in 1979. He skated over to the Hall of Famer, took off his #7 jersey, and handed it to Esposito in what was referred to as Bourque's "surrendering" of #7 to Esposito. Underneath was a jersey numbered 77, which would become as associated with Bourque as #7 had been with Esposito in Boston. Bourque's new jersey number would eventually join Esposito's in the rafters of TD Garden, as the Bruins retired his #77 following his 2001 retirement.
File:Michael Jordan UNC Jersey cropped.jpg|thumb|left|North Carolina basketball retired numbers in the rafters at the Dean Smith Center
In rare cases, a number may be retired because of the player's endeavors in other fields. For example, former college football star Gerald Ford's number 48 was retired by the University of Michigan football squad under his future career as the 38th President of the United States.
Teams also take numbers out of circulation without formally retiring them, though it is generally understood that those numbers will never be issued again. For example, the Pittsburgh Steelers have only officially retired three numbers: Ernie Stautner's #70, Joe Greene's #75 and Franco Harris' #32. However, they have not reissued the numbers of several of their greatest players since they retired, and it is understood that no Steeler will ever wear them again. For example, Bradshaw's #12 had not been reissued since he retired in 1984. Similarly, except for a pair of quarterbacks in the mid-1980s, the Green Bay Packers have not re-issued Paul Hornung's number 5 since he departed from the team following the 1966 season. The Dallas Cowboys do not officially retire numbers, but it is generally understood that Roger Staubach's #12, Bob Lilly's #74, Troy Aikman's #8, and Emmitt Smith's #22 will never be issued again. Additionally, after Peyton Manning was released by the Indianapolis Colts, owner Jim Irsay stated that no Colt would ever wear Manning's #18 again, though it was not officially retired until 2017. After he departed from the team in 2004, the Lakers removed Shaquille O'Neal's #34 from circulation, only officially retiring it in 2013.
File:Jackie Robinson Retired.PNG|thumb|A plaque honoring Jackie Robinson in Monument Park at old Yankee Stadium. His 42 number was retired for all MLB teams in 1997
Some teams either formally or informally take a jersey out of circulation when a player dies or has their career ended by serious injury or disease. For instance, between 1934 and 2016, the Toronto Maple Leafs only retired a player's number if he experienced a career-ending incident while playing for the team. As a result, they had only retired two jerseys in their history during that time; Ace Bailey's #6 was retired after he suffered a career-ending head injury and Bill Barilko's #5 was retired after his disappearance and presumed death on a fishing trip. The New York Yankees retired Lou Gehrig's #4 after he was forced to retire due to amyotrophic lateral sclerosis. The New York Jets did not reissue the #90 of Dennis Byrd following a career-ending neck injury, and it was understood long before its formal retirement in 2012 that no Jet would ever wear it again. Similarly, after Wayne Chrebet was forced to retire after suffering multiple concussions, the Jets took his #80 out of circulation but have not yet retired it; Byrd and Curtis Martin were the most recent Jets to have their numbers retired as both were done on the same day. After Magic Johnson retired because of his HIV disease, the Lakers retired his jersey #32.
In 2008, Princeton University retired the number 42 for all Princeton Tigers sports teams in honor of Bill Bradley and Heisman Trophy winner Dick Kazmaier. UCLA retired the same number in 2014 for all Bruins sports teams in honor of Jackie Robinson, who had played in four sports at the school before his Hall of Fame baseball career. Although Robinson never wore #42 at UCLA, the school chose it because of its indelible identification with Robinson.
In 2011, Michigan Wolverines football unretired all of the numbers that it had retired to create legends jerseys worn by its best players. The unretired jerseys were Bennie Oosterbaan's No. 47, Gerald Ford's No. 48, Ron Kramer's No. 87, The Wistert Brothers' No. 11 and Tom Harmon's No. 98. In 2015, the Legends program was discontinued, and the numbers re-retired.
On December 18, 2017, Kobe Bryant became the only player to have had two numbers retired by the same franchise, Los Angeles Lakers.
Different team retirements
Sometimes, if a player had been part of multiple franchises, both may elect to retire the number the player used per team. For example, Hank Aaron has the number 44 retired by both the Atlanta Braves and the Milwaukee Brewers both because of his achievements and because he wore the same number for both teams.In some cases, a team may retire a number in honor of a player that never played for them out of respect. Following Kobe Bryant's death in 2020, the Dallas Mavericks announced that number 24 would no longer be issued by the team. While the number has not been issued since then, it is not honored in the rafters as an official retired number. Similarly, the New Orleans Pelicans retired number 7 in honor of Pete Maravich's basketball contributions to the state of Louisiana, both during his college career at Louisiana State University and his professional career with the city's former NBA team, the New Orleans Jazz. In addition, from their establishment in 2004, the Charlotte Bobcats did not issue number 13 out of respect to Bobby Phills, who played with the city's former NBA team, the Charlotte Hornets, who had already retired the number in 2000. In 2013, the New Orleans Hornets changed their name to the Pelicans. The following year, the Bobcats also re-branded, bringing the Hornets name back to Charlotte. Additionally, the original Charlotte Hornets' history from 1988 to 2002 was transferred to the renamed team. In 2014, the Pelicans returned the number to circulation, while the new Hornets had the number retired; it currently hangs from the rafters of the Spectrum Center. In the 2016–17 season, Cheick Diallo became the first Pelicans player to wear #13 after its reactivation.
League-wide retirements
Three players in the major North American sports leagues have had their numbers retired by all teams in their respective leagues, those being Jackie Robinson, the first Black player in the modern era of Major League Baseball, Wayne Gretzky, argued by many to be the greatest hockey player in NHL history, and Bill Russell, the most successful player in NBA history in terms of total championship wins.Robinson had his number 42 retired league-wide in 1997. However, players who were wearing the number at the time were permitted to retain it for the duration of their careers, if they chose to do so. Mariano Rivera, the last remaining player to wear the number, retired at the end of the. April 15 has been designated as Jackie Robinson Day to honor the anniversary of Robinson's MLB debut; on this day, all players, managers, coaches, and umpires wear 42.
Wayne Gretzky, who retired as the National Hockey League's all-time leader in goals, points, and assists, had his number 99 retired league-wide at the 2000 NHL All-Star Game. On August 11, 2022, the NBA announced that it would retire Bill Russell's number 6 jersey league-wide, allowing players already wearing the number to continue to do so.