I’d change that “sometimes” to “usually”. MLB teams will usually “assign” numbers to minor league players that have a chance to be called up during the season, but generally won’t assign them numbers anyone else might want (i.e., low numbers) in case they make a trade for a player who wants to keep his old number. I looked at the Pittsburgh Pirates’ roster for this past season, and of the 10 players they had who made their debut this season only 3 had numbers below 40. I think getting to pick your number is one of the benefits of not being a rookie.
I was going to ask about the Stooges numbers, thanks
Waaaaaaait a minute … I thought Defensive players could wear any numbers they darned well pleased! (That’s a rule that goes back to the days when the manic specialization of modern football had not yet descended upon us, and the same 11 guys would often play for the entire game with no substitutions. Can’t very well impose defensive numbering requirements with only 1 set of player jerseys.)
NFL Rules:
http://www.jt-sw.com/football/pro/index.nsf/Documents/0-jers-nums
College Rules:
Question: Is there a set of rules governing which players can wear which jersey numbers?
Answer: Yes, for the offense. Ends are numbered from 80 to 99. Other linemen are numbered from 50 to 79. The other 4 players are numbered from 1 to 49.
http://homepages.cae.wisc.edu/~dwilson/rsfc/intro/answers.shtml
Nope. When Brian Boswell came to the Seattle Seahawks the team and Bosworth tried to get the rules changed to allow him to wear number 44, the same number he wore in college. When that didn’t work, the Seahawks tried to invent a new position for Bosworth that would allow him to keep his number. That also did not work. He ended up wearing #55.