Last year, the Sox were essentially kaput by the time September rolled around anyway--4 games under .500, 3rd place, and 6 games out--so as they bumbled through some difficult road trips and getting swept at home through the Twins, there wasn't much fretting over the loss of a race they never had the horses to be a contender in. That said, the offense curled up and died and Buehrle went through well-documented post-Perfect Game troubles.
In 2008, the offense slumped noticeably after Carlos Quentin punched-out for the season, and in 2006, a season of pretty horrible pitching--and an unholy allegiance with Javy Vazquez--finally caught up with the squad. But what happened this year?
The defense definitely suffered hiccups during crucial moments (and Teahen returned) , Floyd has regressed while Garcia went down with an injury, and the offense has stranded somewhere around 1900 runners this month.
None of this particularly explains why the White Sox can't seem to close out a season with something meaningful at stake. The stathead explanation is that this is all coincidence, or its simply the time where the Minnesota Twins' superior talent finally starts outweighing everything else. Someone looking to blame Ozzie might suggest that his abrasive style wears his team down after the long haul, or perhaps the notorious warm-weather hitters on the roster have leveled off as things have become, you know...less warm. Alexei certainly isn't having a good month, Rios has been pretty average since May, and Manny is going through a period of struggles because: his timing's off/he's still a little hurt/he's possibly washed-up/who the hell knows with him? He's Manny Ramirez.
I personally prefer the explanation that blames Kenny Williams, that being saddled with an aging roster every year means the White Sox are consistently wearing down physically by the end of the season, a fact that wasn't helped this season by a crippling lack of depth that forced Ozzie to ride certain players into the ground. I can't help but notice that three of the key guys (Putz, Thornton, Garcia) who went down near the end were all over 30 and giving the Sox more than they were expected to.
All these explanations are better than the simpler concept, that when the season winds to a close and the games have to be had, the White Sox have just tended to be losers.