Chicago is no stranger to guys who know how to pull off incredible reversals, and the South Side had three Rudolph Herings on their pitching staff last season.

I've been working on finishing up the player previews for White Sox Outsider 2011, and there's one trend I'm seeing that caught me completely by surprise -- right-handed pitchers who are more effective against left-handed hitters.

More specifically, righties who used to get whomped by lefties are now retiring them with more ease than their right-handed counterparts.

Three examples:

2008 PA 2009 PA 2010 PA LHB .259/.340/.485 427 .232/.295/.385 419 .259/.312/.361 439 RHB .226/.279/.380 451 .256/.307/.372 378 .292/.354/.422 359

Floyd had problems against lefties in 2008, but he erased the divide in 2009. Still, that didn't prevent teams from loading up on lefties in 2010, and all Floyd did was reverse the split entirely.

The rise in his ability to retire lefties correlates nicely with the effectiveness of his slider, especially if Pitch f/x mistakenly IDs his slider as a cutter (paging Colin for confirmation). But when lefties are getting more and more cracks at him, I wonder if he's seeing a dilution of hitting talent, with teams using an uneven platoon against him just for handedness' sake - like, Jerry Owens-caliber talent.

The Minnesota Twins serve as a counterexample. Floyd had nothing against the Twins last year, losing all four starts with an 8.04 ERA. He can't blame the slow start, because they never met until after the All-Star break. The Twins simply have a lot of left-handed hitters, and they're all legit.

No. 2: Tony Pena

2008 PA 2009 PA 2010 PA LHB .296/.340/.467 150 .288/.378/.500 135 .244/.354/.356 215 RHB .267/.309/.387 163 .280/.297/.357 177 .308/.349/.466 230

Unlike Floyd, Pena's process hasn't been a gradual one. His splits had widened for years, and all of a sudden -- bam! -- it's the right-handed hitters who are doing the pounding.

In this case, it seems to me that cowardice has its virtues. Pena was a fraidy-cat against lefties, as evidenced by the walk-to-strikeout issues (30 BB, 25 K), and the fact that he walked them twice as often as he did righties. BABIP also had a big split, although it stands to reason that if he's nibbling so much, the contact might be weaker.

It worked for him because he rarely pitched in anything resembling high leverage, but I wouldn't count on this working for him with the bases loaded in a tight game.

2010 PA LHB .207/.293/.220 92 RHP .298/.390/.421 143

You'd think that with Santos' fastball-slider combo that he would be death to righties, but as Colin pointed out, his changeup is pretty good, and it aligned perfectly with his low-and-away-at-all-costs beginner's-kit approach. Sample size is also in play, but BABIP (.304) isn't.

It'll be interesting to watch what Santos does against lefties. I'm guessing the splits won't be this severe, but he could be a guy like Scott Linebrink -- no, not in that way, calm down -- where he's naturally predisposed to getting lefties out a little bit better.

But if he somehow maintains this split ... and if Tony Pena induces a lot of unimpressive contact amid the walks ... and Chris Sale and Matt Thornton are both in the bullpen ... then why is Will Ohman here again?