PECOTA Was Right About The Sox

by Keith Glab,
August 22, 2007

I don't have the exact quote, but earlier this week, Ozzie Guillen said that no one could have predicted that the Chicago White Sox would have a season like this one.  That is a load of malarkey.  The folks at Baseball Prospectus saw this coming with their 72-90 predicted record.  As it turns out, those PECOTA projections may have been a little generous.

The White Sox carried a .448 winning percentage into play on August 22nd after winning two games in a row.  PECOTA had them pegged for a .444 winning percentage.  Nail-on-the-head stuff, right?  The thing is, BP's system predicted the Sox to score 765 runs while allowing 857.  Their current numbers project to 696 runs scored and 839 allowed.  So in Ozzie's defense, even PECOTA did not believe the Sox would be this bad.  However, I seriously doubt that the Ozeroo was talking about anything besides the team's record when he made his comments to the media.

Several White Sox players were made aware of Baseball Prospectus' predictions during spring training, and they all laughed them off.  Admittedly, so had I and the rest of us here at Baseball Evolution.  Of our six prognosticators, Asher put the South Siders the lowest with 79 wins.

Anyway, the folks at Baseball Prospectus appear to have correctly dubbed the Sox' pitching, but overestimated their offense by nearly 70 runs.  That's significant.  Let's take a closer look at some of the Sox' offensive performers:

Tadahito Iguchi - Predicted: .288/.357/.437 Actual: .251/.340/.382    

The two interesting things about the Iguchi prediction are that the OBPs are reasonably close despite major discrepancies in AVG and SLG, and that Gooch is now approaching his projections with the Phillies.

Jermaine Dye - Predicted: .286/.354/.525 Actual: .245/.309/.485

The Sox had faith in Dye after an abysmal first half, whereas they did not show the same patience with Iguchi.  Dye has rewarded them with a stellar second half, and the Sox rewarded Dye with a contract extension.

This does not change the fact that Dye's overall numbers merit serious Dave Kingman Award consideration.  It was obvious that Dye was going to drop off from 2006's numbers, and when I first looked at the Sox' PECOTA projections, I thought it odd that they had predicted a relatively gentle decline for Dye, yet still pegged the Sox for 90 losses.

Darin Erstad - Predicted: .238/.294/.325 Actual: .268/.325/.351

Here's a case where the Sox underestimated a player's offensive contributions.  Another reason I didn't buy into these predictions back in March was because they assumed that Erstad would get 308 plate appearances despite putting up abysmal numbers.  The abysmal numbers I could see, but with Brain Anderson, Jerry Owens, and Ryan Sweeney as viable alternatives, it just didn't make sense to me that the Sox would stick with such a player.  But in truth, Erstad's numbers aren't that much better than BP's projections, and he would actually have had a lot more playing time had he been able to stay healthy.

Joe Crede - Predicted: .268/.318/.477 Josh Fields - Actual: .245/.297/.455

PECOTA definitely overestimated Crede, who was coming off a career year, but had severe back problems.  Fortunately this system, Josh Fields came in and exceeded Crede's performance enough to approach the projection for Crede.  But the veteran's 167 dismal at bats at the start of the year don't just go away; they are a big reason why the Sox have not scored many runs this year.

Juan Uribe - Predicted: .266/.310/.459 Actual: .222/.277/.362

If PECOTA had predicted Uribe's actual rate stats, I would have launched the same protest that I did with Darin Erstad.  No way a team sticks with someone who has a sub-.280 OBP, right?  But the Sox had no one ready to replace the struggling Uribe in their farm system, and Alex Cintron seems to have spent most of the season on the BL.  As it turns out, PECOTA was generous to Uribe, as we might expect from a system named after a weak-hitting shortstop, and he is a big reason why the overall runs projection was a little high.

Pitching-wise, PECOTA greatly underestimated Javier Vazquez, Mark Buehrle, and Bobby Jenks, but actually overestimated Jose Contreras and much of the Sox' bullpen.  Obviously, things evened out to a very nice overall prediction for the staff.

PECOTA seems to do better overall with a team's projection than it does with each individual player.  This makes sense, since it is based on historical trends, and because player performance is more volatile than team performance.  I'm not saying that I will drastically change any of my pre-season picks for 2008 based on what PECOTA puts out, but if we do have a 20-win disparity on a particular team, it may give me a little more pause now.

Disagree with something? Got something to add? Wanna bring up something totally new? Keith resides in Chicago, Illinois and can be reached at