There are a lot of projection systems floating around the nerdy baseball universe. Here on FanGraphs, we host a lot of them, including ZIPS, Steamer, Oliver, Marcel, and the Fans projections, and then there’s other systems like CAIRO and PECOTA that are hosted elsewhere. Of all the baseball projection systems, PECOTA is probably the most famous because it was created by Nate Silver, and Nate Silver is now pretty famous for his post-baseball career. So, when PECOTA releases their annual projections, mainstream writers pay attention. And Chicago writers, particularly, like to talk about PECOTA’s projections, mainly to remind everyone how wrong they’ve been about the White Sox.
For instance, here’s a piece by a local radio anchor that trots out all the usual ad hominem attacks about geeks and their numbers. And here’s another one of this year’s entries, which just gives up on factual information completely:
What is it about the White Sox’s rosters and farm system that Baseball Prospectus doesn’t like?
To answer that question, I decided to do research on who writes these inaccuracies year after year. What I found shocked and disturbed me.
It’s Nate Silver.
My whole world of reality collapsed at that moment.
How could it be the guy I religiously read for pinpoint accuracy in politics? How could it be that Silver is an accuracy genius in politics, but yet when it comes to the White Sox he transforms into the accuracy of a Republican pollster?
After composing myself, I discovered a possible reason. Silver lived in Chicago for many years near Wrigleyville and is rumored to be a Cubs fan.
Maybe being a Cubs fan is a weighted bias even Silver’s methodology can’t overcome.
I’m not here to defend PECOTA — BP can do that if they’d like — but I will just insert some facts into the discussion. Like, for instance, that Silver grew up in Michigan as a Tigers fan, not a Cubs fan. Or, that Silver hasn’t been in charge of the system since 2009, and the code has been essentially rewritten since he left. And, of course, it would be remarkably silly for any forecaster to create a system that intentionally downgrades the projections of a specific franchise, since that would simply make the system less accurate and hurt his own credibility. The idea that PECOTA has some kind of anti-White Sox bias because Silver went to the University of Chicago and attended some Cubs games is worthy of the tin foil hat brigade.
That said, I do think it’s interesting that the White Sox have regularly outperformed PECOTA’s expectations, and I think it’s worth actually investigating, as opposed to what Michael Tomaso did. So, let’s investigate the White Sox overall performance since 2005.
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