I think a major league pitching coach's impact is negligible. He might be able to help one player achieve more, but get less production from another guy. Players make the coaches and managers, at least at the major league level. Dave Duncan gets a lot of credit in St. Louis, but the reason he does is because the team wins more games. The guys he's getting credit for the last few years haven't really been any better or worse in St. Louis. Wellemeyer is not good, Lohse and Pinero are O.K, but they aren't any different from when they pitched elsewhere. They have two legit aces. They could pair up any three average starters with Carpenter and Wainwright and be solid. I'll give him credit for Suppan. Suppan's the only one I found so far that had decisively better numbers in St. Louis. Maddux got a lot of credit for guys like Turnbow, Davis, and Dan Kolb. Turnbow also lost what he had under Maddux, Davis has repeated a few decent years in other places, and Kolb had about 50 good innings in his career. So that being said I'm not sold on the pitching coach being of significant importance. At the minor league level, Yes, major league, No.