Luck as it relates to the Sox starters

So Joe Sheehan did kind of the same thing, but I'd been working on some of this for a little while, so I figured it might be worth posting anyways. I just wanted to take a look at various elements of the White Sox and see if there were any inidcators that they were due for a fall or if I could relax, confident that the Sox will remain in the race on through the summer. I'm starting with the pitching staff.

When looking at luck for pitchers, the three areas of focus are Batting Average on Balls in Play (BABIP), the Home Run-to-Fly percentage (HR/FB), and the Line Drive Percentage (LD%). In a normal, average world, BABIP ought to sit around .300, HR/F should be approaching 11%, and LD% should be a bit under 20%. It’s been demonstrated that pitchers have no control over these numbers, so significant variations from these norms indicates luck either way.

The one pitcher on the staff having no success is staff ace and favorite player of TC Fleming, Mark Buehrle. The luck points to a number of interesting things for Buerhle. His LD% and HR/FB rates (18.9% 8%, respectively) are right where they should be, but his BABIP is a suspiciously high .328. One way to see the effect of this sort of thing is to look at FIP vs. ERA. FIP stands for Fileding-Independent Pitching and uses the three factors over which a pitcher has control (strikeouts, walks and home runs allowed) to say how many runs a pitcher would be expected to give up over nine innings separate from the performance of his defense. Basically, it takes out the effect of BABIP. Mark Buehrle’s ERA this year has been 4.82 while his FIP has been 3.93. He has continued to strike out and walk batters at his career rates, but he has cut down on the home runs allowed. There is precedent for this: his home runs allowed per game are almost identical to what he allowed in 2005, his career year. Once his BABIP inevitably evens out, that ERA will drop, and the Sox will achieve still more success.

With Javier Vazquez comes more confidence that the pitching staff is for real. With a 2.62 FIP, Vazquez places second among all pitchers in the Major Leagues. And here’s the thing: his 21.5 LD% and .323 BABIP show he isn’t really getting any bounces. Well, he actually kind of is. His 4.8% HR/FB shows that he isn’t giving up nearly as many home runs as his number of fly balls would indicate. Home runs are pretty costly, so when they do start leaving the par, it’ll be bad. That badness, however, ought to be offset somewhat by his BABIP and LD% falling back to normal levels. In the end, the home runs ought to be costly enough that his FIP will rise, but he could still end up with an ERA less than his current 3.43. He’s pitching at an All-Star level, and that’s not likely to stop.

On the other side of the ledger, we find Jose Contreras. Contreras ERA has been better than last year, but he isn’t striking out any more batters than he ever has—in fact, it’s less. The only noticeable shift in his numbers lies in the number of home runs he has allowed, and with a HR/FB of 4.2%, that isn’t really anything he’s doing well. His .260 BABIP and 18.8 LD% show he has nowhere to go but down. His ERA is going to balloon, and it’ll probably do it soon. I’m expecting an ERA somewhere in the mid 4’s.

Going in to the year, the fate of the staff--and to some extent, the team--looked to hinge on the two young starters, John Danks and Gavin Floyd. Were they to live up to their draft slot in ways they had not thus far, the Sox could really improve. With both sporting ERA's under 3.00, both appear to have done just that. Digging deeper, however, indicates only one is likely to continue to perform at such a level.

John Danks certainly indicated he might have something last year and has continued on that path. Right now, his still-excellent 3.29 FIP is a bit higher than his 2.94 ERA. His LD% and BABIP (16.5% and .288) bear that out, indicating some luck. His HR/FB is a fluky 5.7%, but his HR/G are down to such an extent that not all of that can be attributed to luck. He is, in fact, getting a lot more ground balls this year (51.3% Groundballs this year, compared to 34.8% last year). He's also been cutting down on his walks. Danks is improving. His BABIP, LD%, and HR/FB all indicate regression but not a ton of it. His ERA should stay under 4.00.

The bad egg, then, is one Gavin Christopher Floyd. Looking at every stat but ERA, this is the worst year of his career. He's striking out two less batters per nine innings than he was last year, 6.0 to 4.1. He is walking two more batters per nine innings than last year, 2.3 to 4.3. His home runs allowed per nine innings is down, but that can be expected, given the drop in HR/FB (17.3% in '07 to 6.3% in '08). His BABIP is .193, and his LD% is 11.8. His ERA is 2.92 while his FIP is 5.02. This is all to say that he should be buying lotto tickets in bulk. Floyd is about to get rocked. Hard.

Four of the five starters discussed here have HR/F rates that should cause concern—and a good bit of it. While pitchers can get lucky for a whole year (18 pitchers finished 2007 with a HR/F under 10%), none of them stay as lucky as Contreras, Danks and Vazquez are right now (no one finished 2007 with a HR/F under 6%). And, of course, it’s not the sort of thing one wants to depend on. But with the BABIP’s evening out in the favor of Buehrle and Vazquez, they shouldn’t be so bad off. As Sheehan noted, they're not giving up walks.