(Obviously this is only applicable to those teams who haven't had the sim god on their team.)
It's rare in any league to see a guy of his talent dealt so often (relatively speaking compared to the talent) and when you factor in how he doesn't seem to want to have a contract higher than your average 2.5 star SP... it's just baffling. Free agent bust Jonah Axelrod took home a lot more change than McC has ever bagged in one signing.
Granted, he is older now, but it really is one of my regrets as a GM in this league. A career ERA of 2.93 of five teams played for. I know with that talent it's tempting to deal for a team needing to rebuild (as many of those teams were doing by trying to get a big return on their big asset), but it's still surprising to me that no one managed to keep him for 7 or 8 years (the longest tenure was of three and a halft years in New York.)