If you like baseball cards, I recommend checking out a blog called Cardboard Junkie. Recently, the author posted this 1983 Topps Gaylord Perry card as part of his analysis of that particular set:
He also noted that Gaylord Perry had more career wins than the entire Mariners franchise when he joined the team. I mean--Perry had more wins than the Mariners in their entire history up until that point. A quick check confirms that before the 1982 season, Perry had 297 career wins while the Mariners had (1977-1981) just 290.
This got me to thinking about how often this happens, namely that a pitcher joins a team and has more career wins than his new franchise in its history. Of course it must happen pretty often. Virtually every pitcher with major league experience has more wins than an expansion team. Look for example at the 1993 Florida Marlins. They had zero franchise wins when the season started, but obviously most of the pitchers (such as Charlie Hough, Jack Armstrong, Bryan Harvey, etc) had at least 1 career win before 1993.
So we could find many examples of pitchers who fit this description. However--are they any who had more than Perry's 297 wins when he accomplished this "feat"? It would have to be a 300-game winner going to play for a pretty young franchise. The first guy who pops into mind is Randy Johnson, who joined the Diamondbacks in 1999 after they had won 165 games in their first 2 seasons. However, at that time, Johnson had only 143 career wins.
Anyway--can anybody come up with a pitcher who beats Perry's total of 297?