Bill Russell’s No. 6 Joins Rare Class of Retired Jersey Numbers

Bill Russell, who died last month at 88, is getting a rare honor: His No. 6 will be retired, not just for his team, the Boston Celtics, but for the entire N.B.A. Among major sports, only Jackie Robinson’s No. 42 in baseball and Wayne Gretzky’s No. 99 in hockey have been retired leaguewide.

That raises some questions, which we will endeavor to answer.

What about the N.B.A. players who are currently wearing No. 6?

These players, among them LeBron James of the Los Angeles Lakers, may continue to wear No. 6 until they retire. But no new players will be issued the number. The same rule applied when Robinson’s number was retired baseball-wide in 1997. Mariano Rivera of the Yankees was the last player still wearing No. 42 every day when he retired in 2013.

There have been other N.B.A. greats who wore No. 6, right?

Yes, quite a few, including Julius Erving. But the leaguewide retirement honors only Russell.

Will anyone join Russell, Robinson and Gretzky?

There has been a push for baseball to retire Roberto Clemente’s No. 21 leaguewide to honor his humanitarian work. In particular, many Puerto Rican players have said they would not wear the number. Commissioner Rob Manfred has said that Clemente is honored in his own way with the Roberto Clemente Award, given for sportsmanship and community service.

What teams have retired the most different numbers?

In the four most venerable men’s leagues, the Yankees (21, with more planned this year), Boston Celtics (23), Montreal Canadiens (15) and Chicago Bears (14). Many W.N.B.A. teams have retired the numbers of their best players, including the Los Angeles Sparks, who retired Lisa Leslie’s No. 9.

What are the lowest cardinal numbers that no team has retired?

In baseball, 38; football, 2; men’s basketball, 26; and men’s hockey, 25.

What things other than numbers have been retired?

A number of teams have retired a symbolic microphone for a legendary announcer, such as Vin Scully for the Los Angeles Dodgers and Chick Hearn for the Los Angeles Lakers. Some baseball players who competed before the dawn of uniform numbers are honored numberless: Rogers Hornsby by the St. Louis Cardinals and Grover Cleveland Alexander by the Phillies, for example.

Are there any unexpected retired numbers?

Of course the Chicago Bulls retired Michael Jordan’s No. 23. But so did the Miami Heat, even though Jordan never played for them. Pat Riley, the team president, said, “We retired his jersey because I had so much respect for him.” Pete Maravich never played for the New Orleans Pelicans, but he had played for Louisiana State and the New Orleans Jazz, so the Pelicans retired his No. 7 anyway.

Kobe Bryant wore No. 8 for the first half of his career and No. 24 for the second. The Lakers retired both numbers for him.

The Yankees had two great catchers who wore No. 8: Yogi Berra and Bill Dickey. Now, the number is retired to honor both of them. Among others who share a retired number: Greg Maddux and Ferguson Jenkins, No. 31 for the Cubs; Lem Barney, Billy Sims and Barry Sanders, No. 20 for the Detroit Lions; Guy Lapointe and Bernie Geoffrion, No. 5 for the Canadiens.

No. 00 has been retired (Robert Parish of the Celtics, for one), but so has 1,223, to honor the coaching victories of Jerry Sloan for the Utah Jazz.

What about outside North America?

Although the tradition is not as widespread in world soccer and other international sports, some clubs have retired a number or two. Among the notables: Johan Cruyff, No. 14 for Ajax; Bobby Moore, No. 6 for West Ham; and Diego Maradona, whose No. 10 was retired by Napoli.

It’s harder for international teams. In an event like the World Cup, the 23-player squads have been required to number their players from 1 to 23, so retirement has not been an option. (Rosters were expanded to 26 players for this year’s tournament.) At the 2018 World Cup, Neymar wore Pelé’s No. 10 for Brazil, and Lionel Messi wore Maradona’s No. 10 for Argentina, numbers one certainly would expect to be retired.

Many soccer clubs also don’t assign No. 12 in honor of their fans, whom they consider “the 12th player” on the pitch. That’s the same reason the Sacramento Kings and the Orlando Magic of the N.B.A. had already retired No. 6.

Now, thanks to Russell, No. 6 soon will leave other teams’ courts, too.