for those of you who don't have the patience to read Eugene Styles post. I'll briefly summarize. He proved that if two staffs had the same era and whip with the same number of Pitchers, that if one had Prior last year and one Gagne they would still have the same era. Granted, Gagne's ERA was lower than Prior's, but since Prior pitched more innings it still has the same effect.
I'm the artist formely known as Manutd016