Over the past few days, you can't escape arguments like this one if you've read anything about the A's-Rockies trade:
Matt Holliday is a creation of Coors field. His career line on the road is only .280/.348/.455! That's an OPS of .803, or what Cliff Floyd put up in 2008.
I'm not going to try to convince you that Holliday's numbers aren't greatly Coors-inflated (because they are), but quoting his road line is a horrible way to judge his true talent level. Why?
- Players perform better at home than on the road, all else being equal. That's what causes a home-field advantage! Across MLB in 2008, the average home OPS was .770 while the average road OPS was .730.
- Holliday's away parks don't include Coors field, while all other National Leaguer players' away parks do. In other words, his away parks lean towards pitching parks, pulling down his numbers.
- Using only road numbers ignores more than half of the data we have on Holliday. How is that a good thing? It's a much better idea to use ALL the data available and do a proper park adjustment.
- There very well might be a "Coors Hangover Effect". Since breaking balls don't break as much and flyballs are rewarded big time in Coors, Rockies hitters might be hurt on the road because they can no longer count on those advantages. I haven't seen any conclusive studies for or against this theory, but the Rockies do tend to have more extreme home/road winning percentage splits than other teams.
- Why are we using career numbers? Why not the most recent seasons? Holliday's road OPS numbers from 2006 through 2008 are .819, .860, and .892. That's an average of .857 and a 5/4/3 weighted average of .863. (Thanks to reader dougdirt who provided #5 in the comments.)
Listen, I agree that Matt Holliday's numbers are grossly exaggerated by Coors Field. And I agree that he'll probably be signed for too much money. But there's a right way to park adjust statistics, and quoting road stats is far from that right way.
Addendum: If you take the weighted road-OPS average of the past three years from #5, add .020 points of OPS for #1 and .020 points of OPS for #2, you get a .903 OPS. That's .150 points better than average, or three wins over 600 PAs. Add in two wins for replacement level and subtract half a win for position/range/arm and you get a 4.5 WAR player. Not a bad estimate.
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With that rant over, there's a question I have for those of you who think you have good baseball eyes or have mad Pitch f/x skills. One theory about why Holliday might benefit more from hitting in Coors than the average player is that he's a bad at hitting curve balls. Since curve balls don't curve as much in the thinner air, that eliminates a large weakness he has. Do you buy that?