Yesterday, I wrote in this space about the odd fact that the Chicago White Sox, who are on pace to win 107 games, feature an offense that could most charitably be described as mediocre. Giving them all due credit for their fine hitting in the clutch, team speed, and so forth, the Sox offense is barely of the quality usually associated with .500 teams, let alone .660 ones.

So, even after it is noted that the competition in the American League Central is not all that it might be (and that the Sox are a mere 33-26 outside their division), most of the credit for the team’s extraordinary season must go to the pitching and defense, which has been by far the best in the league. This leads to the mystery at the heart of the White Sox’ season: How exactly is it that a pitching staff – and more specifically, despite stellar bullpen work, a rotation – expected by almost no one outside of Bridgeport to be much better than average, has had a season reminiscent of those enjoyed by the great Braves staffs of the 1990s?

The pitching numbers on the Southside aren’t all that impressive. Pitching in a good hitter’s park, the Sox staff leads the league in ERA but isn’t near the top of the pack in any other major category. In road games, the team’s ERA is sixtenths of a run lower than any other teams’, but they still don’t dominate in any other category. Sox pitchers don’t strike out huge numbers of batters, aren’t on the whole notable for their control, and don’t even allow an unusually low batting average.

The Sox are notably above par in only one area – home runs allowed. Their road total of 32 is absurdly low, by far the best in the league. Their home total of 65 is the highest in the league, but still excellent considering that U.S. Cellular Field inflates home runs by about 40%, the highest figure in baseball right now.

The Sox’ ability to keep the ball in the park is clearly the key to their success. The rotation was assembled with an eye more toward movement than velocity, and that was a solid plan that’s paid off better than anyone could have hoped.

Ace Mark Buehrle, whose prime virtues are his durability and ability to change speeds with and locate four generally unimpressive pitches, has given up only six home runs in 85 innings at home, and two in 65 road innings. That’s the result of trying to induce bad contact – the typical Buehrle outing features plenty of squibs, dying quails, and weak grounders hit off the thin end of the bat, but almost no solid contact that results in drives over the fence.

No. 2 starter Jon Garland is thought by many to be a fluke because of his low strikeout totals – he’s racked up just 63 Ks in 133 2/3 IP – but like Buehrle, his fine results (15-4, 3.19) are the result of avoiding walks and keeping the ball down consistently. The difference for Garland is that he has an incredible sinker, reminiscent of the one Kevin Brown threw in better days, and so the low strikeout totals aren’t really a concern. A batter hammering a sinker into the ground is just as good as a strikeout, and won’t end up in a home run. Garland has allowed just 12 this year, only four of them on the road.

Freddy Garcia shows the exact same pattern. In 146 innings, he’s struck out just 101 batters, but he doesn’t issue many walks. On the road, at least, he’s as stingy with the long ball as anyone, giving up just four in 79 innings. His problem is that he falls in love with his changeup, which, when left up, can simply be tomahawked into the stands at U.S.Cellular. This has led to an unsightly 5.00 ERA in Chicago, largely the result of allowing nearly two homers per nine innings there.

The last of the team’s four rotation mainstays, Jose Contreras, again fits the mold. Like Garcia, he gives up nearly 2 home runs per 9 at home, but does much better on the road, and like all the Sox’s starters, he has a rather low strikeout rate – 89 in 120 2/3 IP. Yankees fans frustrated by their team’s lack of pitching might note not only Contreras’s respectable 4.36 ERA, but the fact that he’s actually harnessed his stuff in Chicago. He’s showing a commitment to his fastball and a willingness to attack hitters when in a bind, rather than passively nibbling at the corners of the plate with off-speed pitches.

In sum, while credit goes to the bullpen and to the Sox surprisingly rangy infielders – particularly shortstop Juan Uribe – the staff’s success can be chalked up to the ability of the team to identify healthy, durable starters with a penchant for keeping the ball down in the strike zone. Starters who throw low strikes don’t give up home runs and walks, and don’t run up big pitch counts, so they go deeper into the game and keep the team’s worst relievers out of key situations.

The value of all this can be seen in what I think is the rotation’s most impressive statistic – innings. Buerhle, Garland, Garcia, and Contreras have racked up 547 1/3 IP, as compared to the 455 amassed by the Yankees’ top four starters. That’s 100 innings in which the ball is in the hand of a good starter rather than someone like Wayne Franklin, Tim Redding, or Scott Proctor.

Like most successful ideas in baseball, the notion of lining up starters who fit your home park, don’t get hurt, and keep the ball in the yard is hardly revolutionary, and is a matter of execution more than anything else. It’s not as if teams go looking for pitchers who give up lots of home runs and have balky shoulders.

Still, it’s worth asking: Had the Yankees decided to take the same approach the Sox did, would they really have acquired the likes of Kevin Brown, Carl Pavano, and Jaret Wright, known by all to pose threats to the sanity of area doctors and/or the health of fans sitting in the bleachers? And had they followed that approach with the same tenacity as the Sox, would they be on pace for 107 wins?