So part of your reasoning is based on looking at carrer ERA, without looking at full context? Part of this discrepancy is based on Suppan's early career, from ages 20-23, when he was in the major leagues as a below average pitcher. At the same age, Bush wasn't in the major leagues. It doesn't make a lot of sense to hold this against Suppan when evaluating their current value. Bush's best season was his first season, at partial season of less than 100 innings thrown 4 years ago. His performance certainly looked impressive, but the 3 seasons he has pitched since then haven't really come close when looking at ERA+ (131 then, 103 is the highest since). I'm far from a pitching expert, but I do wonder why Bush hasn't been able to come close to the same results over the last three years that he had in his first. I don't know if he surprised big league hitters with some funky movement and there is now a book on hitting him, I don't know if he just got lucky in his first year, and his recent performance is his true talent. It's true that Suppan has never dominated over a full season as Bush did in his first. Of course, Bush has never done so over a full season either.