PECOTA Was Very Right and Very Wrong about the 2007 White Sox
by Scott Long
For the past few years I've been hammering Baseball Prospectus' PECOTA system, in regards to how off it's been about the Chicago White Sox. 2007 is shaping up like the overall record PECOTA predicted could be pretty close. I was much more optimistic in my thinking and while it still is pretty early in the season, it would appear like I'm going to have to eat some crow on the White Sox. (Most of my other predictions are looking pretty good, though.)
Nate Silver wrote an interesting piece a couple of days back, discussing how the White Sox in 2008 could bounce back, if they make a few key acquisitions. As bad as the offense has been, it's the bullpen that has the White Sox below .500, so I'm doubtful that keeping the status quo there will work in some type of 2008 overall team resurgence.
What I would like to discuss below is this. PECOTA might be right about the White Sox record, but the reason it will happen has little to do with the reasons why PECOTA felt it would occur. To demonstrate why I feel this way, I will list the White Sox players individually. I'm just listing OBP and SLG for hitters and ERA and WHIP for pitchers, as VORP and other statistical tools don't connect with many of the readers here at the Juice Blog. If you want to use those figures, be my guest, but I'm guessing they won't show much of a different conclusion than what I'm presenting.
White Sox Hitters
NAME of PLAYER
I have included only 8 regulars, as Scott Podsednik has been hurt almost the whole season. There have been numerous players filling in for him who have for the most part been so miserable they have made Podsednik look like a valuable component. At this point, PECOTA was off by over 100 points on 6 of the 8 players OPS total. Only Pierzynski and Erstad have been even close to what PECOTA predicted. While I'm not saying I had anymore of a clue that most of the Sox offense would fall off a cliff, it's hard for me to want to give a lot of credit to PECOTA on this subject.
NAME of PLAYER
This category was why PECOTA picked the White Sox to fall apart this year. As generally the case, it is way off on Buerhle and Garland, nearly 2 and half runs off from what it originally predicted for the 2. Contreras and Vasquez are really close, so kudos on them. Danks has been a big surprise, though his ERA won't stay in the 4's if he continues with such a high WHIP. Starting pitching was my big beef with PECOTA at the beginning of the year. Here was my predictions for the Top 4 starters at the beginning of the year.
NAME ERA WHIP
Buehrle 4.45 1.34
Garland 4.15 1.29
Contreras 4.40 1.35
Vazquez 4.25 1.31
NAME of PLAYER
I actually think PECOTA did a pretty good job of predicting impending doom in the bullpen, as when you have a relief corp with this high of WHIP's, you can't be confident in success. Kenny Williams has been spoiled by pitching coach Don Cooper developing damaged pitching prospects the past few years and this year it was like they (Sox Front Office) were Ginger Lynn holding onto Peter North (Sox Bullpen). It exploded right in their faces.
At this point of the year, it appears like I was way off on my 88 win prediction. Some are hailing PECOTA for being right about the White Sox, but if you look at the breakdown on a player to player basis, the system couldn't have been much more wrong. The White Sox of this season are a really bizarre team. This is something that PECOTA and SWOBODA can agree on.
(Author's Note: I'm a huge fan of Baseball Prospectus and I believe that PECOTA is the best statistical prediction tool available. My continuing series on it stems from how I think PECOTA is generally way off in regards to the White Sox.)