TSN: Pinto: Haren trade gives D-backs the bigs’ best 1-2 punch

Another better idea...from Pinto.

Just how good a 1-2 punch to does Arizona have?

Earned runs prevented (ERP) measures how many fewer earned runs a pitcher allows than an average pitcher in the league. The lower the ERA and the more innings pitched, the more runs the pitcher prevents. Ranking teams’ No. 1 and No. 2 starters by ERP shows how well the Diamondbacks are positioned after this trade.

...Webb and Haren, as you see, blow away the competition. I will offer one caveat, however. Haren’s projection of 79 earned runs allowed is based on his career in Oakland, a good park for pitchers (park factor 0.93). He is moving to a park that favors hitters (Chase Field’s park factor is 1.11). Adjusting his earned-runs-allowed projection for this brings the projection up to 97 runs (79*[1.11/0.93]).

That would reduce the Webb-Haren combo to 54.6 earned runs prevented, still best in the majors.