An issue has arose in the past couple days about an offer I made a week earlier when I was trying to add an inexpensive starting pitcher to my keeper list in my 12-team 4x4 AL-only keeper league. (Should there be a standard short form like "124AK" for 12-team 4x4 AL-only keeper league? "165MN" would be a 16-team mixed league non-keeper league.) Ultimately, I accepted the Joe Blanton and Fernando Cabrera for Jorge Posada and Jesse Crain offer. (My doubts are chronicled here.)
The offer that has boomeranged was one I initiated - $5 Mark Teahen for $5 Brandon McCarthey and the #11 pick in the minor league draft. The other team didn't accept right away. This gave me time to do two things. 1. Accept another offer and 2. re-think the proposal and recognize that Teahen is more valuable than McCarthy. Re-thinking offers I make often leads to my recanting of the offer. Typically, it is because the other team makes a counteroffer that swings the offer clearly into the countering teams favor. At other times, it just involves a slow response. Anyhow, that was the end of that trade discussion until recently.
The team that received the Teahen/McCarthy/#11 offer came back with some offer I do not recall. In the midst of explaining why I thought it wasn't acceptable, I may, may, have responded with an expletive followed by a "no". That is certainly not the way to properly handled negotiations, but occasionally an offer, or counteroffer, appears so hard to tweak and counter that I can respond no other way.
With that setting the tone, I explained that I did not see McCarthy as anything better than a 4.50 ERA starting pitching, and one whose upside in Texas is Kevin Millwood - a 4.50 ERA. The other team, Boogey Blog, found that off-base and provided the standard park factors argument to dispute my back-of-the-envelope projection. (Best case, by the way!) (Here is the link to his side of the story.)
When using my methodology - vast player knowledge combined with ready, fire, aim!, I often go back and double-check what I projected. In 2006, the top Rangers starters were Kevin Millwood and Vincente Padilla. Both pitchers had 4.50 ERAs and WHIPs in the 1.30+ area. (Texas 2006 Pitching stats sorted by games started.) Check.
Next I went back and looked at Brandon McCarthey's stats. He has allowed 30 HRs in 151.2 innings with little difference between the number allowed when he started 10 of 12 games in his rookie season (13 in 67) and the number allowed as a full-time reliever in 2006 (17 in 84.2 IP). As a reliever he had a 4.68 ERA and a 1.30 WHIP. Check.
The key factor isn't park factors, but the difference in the way starters and relievers are treated by their managers. A reliever is used against those match-ups he is deemed to have the most advantage. When that changes, the managers changes pitchers. For a starter, the pitcher faces every tough match-up every time through the line-up until he fails or gets into the later innings, usually the 6th and later, when the manager can begin to use his bullpen to manage the match-ups..
Think about that. McCarthy was brought in as a reliever when the match-up favored him and would be removed when the match-up turned against him. As a starter, he is going to face David Ortiz and Travis Hafner and Jason Giambi and Justin Morneau (to choose four HR-hitting lefties that any manager would remove a righty reliever in favor of a left-handed one) every time until McCarthy is taken out late in the game.