Mark Ellis, hittin' better?

By Jason Wojciechowski on August 29, 2011 at 1:25 PM

Jim Armstrong at the Denver Post writes that Mark Ellis

has worked his way into the conversation when the Rockies' front office addresses the second-base situation this winter. Ellis doubled and singled Saturday, extending his hitting streak to six games, during which he's 11-for-23. He's hitting .285 since being acquired from the Athletics on June 30.

That made me initially react with a snarky "you forgot about park factors!" but take a look at this:

Team TAv wRC+
Oakland .213 52
Colorado .239 93

There's a bit of a disjunction here, where how far below average Ellis has hit in Denver depends on which internet purveyor of advanced baseball statistics you visit. Consider some other second basemen:

Player TAv wRC+
Justin Turner .248 93
Kelly Johnson .239 86

It shouldn't come as a surprise that Fangraphs and Baseball Prospectus have different park and/or league factors, nor that Colorado would end up being a point of dispute between the two. I'd love to delve into this further, but I'm unable to find on either site what adjustments they're actually using for their adjusted stats.1 Fangraphs has a Library article on how they're calculated, and you can sort of piece Prospectus's method together from some related articles that turn up in a search on their site, but without spending more time than I have on my lunch break on the question, that's as far as I can get.

Let the point of this post, then, stand as yet another reminder that the internet baseball community still disagrees on some fairly fundamental points -- all statnerds don't believe the same things, and people like me, who do more relying on research to engage in analysis than actual research itself, should continue to take care to acknowledge the differences in calculations of the various metrics out there. (I'm planning to write my awards-season posts around this very theme -- it's easy to just publish a list of different WAR metrics and come to some consensus, but that's sloppy. We ought to understand why the numbers are different and make decisions for ourselves about which metrics we want to use, or even whether we want to calculate our own metrics and/or try to create a push for certain outlets to change their calculations.)


  1. I am, however, a known internet-search idiot. My Google skills took an incredible nose-dive around the time I turned 25, I think. (That was ages ago.) 

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