I've always though that's a bit of a myth, and that the true one team player has always been somewhat rare. I mentioned in my comment that if someone was really bored they could go through the Hall of Fame list to see how many of them played for one team.
Well, I was bored today.
Of 295 Hall of Fame players (not including the Negro Leagues), only 46 spent their entire career with one team. 15.6%.
Lots of them spent the bulk of their career with one team, but a lot of players tried to hang on and spent one season, even one game (Christy Mathewson), with another team. A few, like Ryne Sandberg, started with one team, got traded early, and played the rest of their career for that team.
I'd say that at least as many who played for one team played for 4 or more teams.
6 of the 46 played in the more modern era, where they could have been affected by free agency. It's easy to assume that free agency would help cause the perception that players don't play for a single team any more. However, one part of the perception is that there are 30 teams, so a lot more trades happen then when there were only 16 teams.
So what about the players on the 2011 HOF ballot? Larkin, Bagwell, Edgar, Trammell, Mattingly. All single team plaeyers. Bernie Williams and Tim Salmon hit the ballot next year. Craig Biggio in 2013. After that most of the top candidates have played for more than one team.
There's only one guarantee. If a Hall of Famer ever played for the Philadelphia A's under Connie Mack, he played for more than one team in his career.
|Pee Wee Reese||SS||NL|
|Cal Ripken Jr||SS||AL|
|46 OF 295 = 15.6%|
|19 National Leaguers|
|27 American Leaguers|