I wrote this on the message board on my Fantasy League page, and I thought the rest of AN might be interested as well. I hope the stat guys and gals among us might be able to add a few things, or rip my essay to shreads if it deserves it. Please keep in mind that most of the readers at my fantasy league have never read Moneyball and don't know DIPS from a hole in Ruby's swing.

Hope you enjoy:

Why have the White Sox had such fantastic pitching to start the season? And will it/can it last?

They lead the American League by a wide margin in Team ERA at 2.90 (the A's are second at 3.71, almost a run more a game). Even more incredibly, their starters have an ERA (even after Mark Buehrle's poor outing Tuesday) of 2.58. Even if we're only talking about 12% of a season, that's astounding.

What's the reason? Let's look at some peripheral stats befeore I dig into my argumnt. Sox starters have allowed only 9 HRs, a great number. They've also only allowed 43 walks, which is above league average. Less astounding are their K/9 rates: Contreras leads the starters with a respectable 6.53, followed by Buehrle at 5.91, Hernandez at 5.48, Garcia at 4.82, and Garland at 3.30. Strikeouts, walks, and home runs are the categories where the pitcher clearly has the most direct effect on the outcome (leaving aside hit-by-pitches). The Sox have been great at preventing the longball, good at avoiding free-passes, and rather poor at getting Ks. That looks like a formula for a good staff, but not the amazing staff the Sox have trotted to the mound. So why have they been amazing?

One answer could be DIPS (Defense Independent Pitching Statistic), or more specifically in the Sox case, BABIP (Batting Average [Against] on Balls in Play). BABIP tracks batters' averages against a pitcher only when the ball is actually put into play, so the stat excludes strikeouts, walks, and HBPs.

Incredibly, the Sox have 4 of the top 12 American League starters in 2005 with the LOWEST BABIP (Hernandez is about 50th). Think about that: 13 AL teams have 8 of the 12 starters, the Sox have the other 4. Jon Garland: .202, Freddie Garcia: .225, Jose Contreras: .230, Mark Buehrle: .234. The A's, the second best ERA team in the AL, have only Joe Blanton in the top 25 in lowest BABIP.

But, isn't that a good thing for the Sox? Not necessarily. Voros McCracken, the guy who invented "DIPS", was the first to theorize that, as unlikely as it may seem, pitchers actually have little if any effect on what happens to a ball once it is put into play. If Alez Rodriguez swings and hits a pitch, it has just as good a chance of falling in (or finding its way through an infield) for a hit whether it was hit against Johan Santana or John Halama. I don't have the energy, time, space, or eloquence to explain here why this is so, so I'll direct you to a couple of resources so you can decide for yourself.

Voros McCracken's original DIPS article:
http://www.baseballprospectus.com/article.php?articleid=878
ESPN's Rob Neyer's Great Column on Voros' Article:
http://espn.go.com/mlb/s/2001/0115/1017090.html (Scroll down to "Wednesday, "January 24" and then read "Friday, January 26")

The problem for the Sox this early season is that they might be, and you knew this was coming, getting lucky. If Voros and others since him are correct, then almost all pitchers given a large enough sample size should conform faily exactly with the league's average BABIP. Even if Sox starters continue the low HR rate and good BB rate, there isn't a snowball's chance in hell that they can keep their BABIP rates so low no matter how "good" they pitch, simply because they cannot affect what happens to a ball once it's hit a bat. This means more hits. More hits means more runs. More runs means more losses.

Do the Sox still have a shot at a great season and the possibility of October ball? Of course. But their torrid pitching simply cannot be sustained at this level over the course of a season.