Great, I'll use B-Ref then, instead of the Fangraphs version I was using (thanks for pointing that out TooLiveBrew, I didn't know where the difference was coming from), because that only improves my argument. Since 2004, Davis has been 8.5 WAR better than Bush, and 3.1 WAR better since the start of last season. Simply put, Doug Davis is better than Dave Bush, by wide margin, largley because Dave Bush is a bad pitcher.