Retiring players' numbers in sports

I don’t watch a lot of sports, so maybe this is a dumb question: If by retiring a player’s number means that number will never be used again, how long will it take before a league runs out of numbers? What happens then, letters? Where do the big leagues currently stand in terms of numbers available, NBA, NFL, NHL, Baseball, etc…?

I guess the easiest way to answer is to provide linkage:

MLB retired numbers
NBA retired numbers
NHL retired numbers

I didn’t immediately find any reference to retired numbers in the NFL.

It’s worth noting that retiring a number generally means no one on that team can use the number any longer. As far as I can tell, Jackie Robinson (baseball) and Wayne Gretzsky (hockey) are the only players in North American sports to have their numbers retired for their entire league.

On that Wikipedia list for MLB that Asimovian gave, I have a question about one particular number (sorry if this is a hijack)

I see that the Yankees retired the number 8 for both Yogi Berra and Bill Dickey. How did this work? Did each have the jersey during different years and then it was retired in honor of both of them?

Yes to that last one. There is only 1 single-digit number the Yankees have not yet retired, and the Derek Jeter #2 ceremony will finish that someday.

The Boston Celtics, who’ve been carried away with this stuff, retired #18 for 2 players.

To the OP, it isn’t an issue, or at least won’t be for a very long time, for baseball, hockey, and basketball, as there are far fewer than 100 players on the roster and there are no rules about which position is entitled to what range. I do believe those leagues have rules limiting numbers to 1 or 2 digits. In the NFL, nearly 100, or even more, players can be in camp, sometimes requiring doubling up. There are restrictions on which numbers go with which position, and most of the allocation can be used up. There are retired numbers in the NFL, but the practical problems it creates severely limits the practice.

#6 isn’t retired yet either, but since that is Joe Torre it will be retired as well. The Yankees may be the first team to need to go to three-digit uniform numbers.

Exactly. Dickey played in the 30s; Berra in the 50s and 60s. The Yanks weren’t quite so keen to retire numbers when Dickey retired, so didn’t consider it for him. But when Berra retired, Steinbrenner was retiring any number he could. I’m guessing that when they decided to retire 8 for Berra, someone suggested they include Dickey, too.

Some NFL teams do not retire numbers, such as the Dallas Cowboys . Instead, they induct players into the Ring of Honor (a huge ring around the inside of the stadium) to display the names of their greats.