By which I mean, a player beloved by one fan base, who ended up starring for a rival in my replay. I'm thinking along the lines of Yaz being a Yankee (he wasn't - he was mostly a Cub) or Willie Mays being a Dodger.
And Mays could have been my selection. He's in the Hall of Fame as a Cardinal, which bothers me as a Giants fan. And he did play one season for the Dodgers. But he also played a season for the Giants, and had better stats there.
So, with that in mind - if you're a Phillies fan, you'll want to look away...
