I thought that one of the updates in the past few years eliminated ERA as a factor of 2B/3B rates. While a pitchers OAV will play a factor in hits allowed obviously, 2B/3B were determined solely by the hitter (and park and normalization obv.). I was never sure if pitchers with good hr/9 rates and/or negative homerun parks would turn those homeruns in to outs or 2B/3B or some combination of both...