So the PECOTA-based projections are out, and it's always fun to pick through them. Sometimes, though, someone takes the numbers and draws an odd conclusion or two. Case in point:
This year they've predicted the White Sox to win 77 games. This should be great news for White Sox fans because Baseball Prospectus has consistently predicted the Sox to be worse than they eventually end up.
Chicago Tribune's White Sox reporter Mark Gonzales did a great job analyzing the last eight years of Baseball Prospectus' predictions.
In the last eight years, the White Sox have been worse than predicted only twice and have averaged over seven more wins a season.
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.
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.
You know, this is the sort of analysis that gives newspaper writers a bad name on the Internets.
Wait, what? This guy writes for the Internets? Oh. The Huffington Post. Okay. I will note that Mark Gonzales, who does write for the newspaper, simply presented the data -- PECOTA-based projections vs. actual records -- without any editorializing. That's not analysis; it's just data, which can be a great place to start. Or, as Tomaso demonstrates, it can be a lousy place to start.
Here's more data: as Dave Cameron points out, a) Nate Silver grew up in Detroit, as a Tigers fan, and b) Silver left Baseball Prospectus in 2009 and PECOTA has been largely redesigned. So, there's that. But then Cameron uses the original data to do something interesting: Instead of blaming the messenger, he wonders if there's a better, less onerous explanation.
In the end, Cameron believes he can explain 50-75 percent of the difference between PECOTA's projections and the White Sox's actual records.
The first, smaller chunk of that percentage is easy: the White Sox have out-performed their run differentials, and that's something that essentially cannot be predicted in a meaningful way. Yes, it helps to have good relief pitchers. But relief pitching explains only a small percentage of a team's variation between run differential and record; luck explains the great majority of the rest.
The second, larger chunk of that percentage is a lot more interesting: the White Sox, and pitching coach Don Cooper in particular, have been incredibly good at keeping their pitchers off the Disabled List. Cameron demonstrates this with all sorts of nifty graphs and the like, but the nut is this: from 2002 through 2011, White Sox pitchers spent fewer than 2,000 days on the DL, while most teams were over 3,000 and some well over 3,000.
That should show up in the projections to some degree, since one of the inputs is games missed in past seasons. But any projection system is going to predict some games missed. So if you don't miss any games at all, you're going to fare better than your projection. This is the story, explaining both the White Sox' over-achieving relative to their projections and, more to the point, their general ability to remain competitive, year in and year out.
To this point, I don't know that anyone's really delved into the organization's methods. But it seems to me that the Tampa Bay Rays aren't the only team that's keeping a precious secret.