Blanton is an interesting pitcher. As his charts show, he, seemingly, has no above average pitch. He's got the lowest K rates across the board that I've seen so far and he survives in large part on smarts. For example, check out his 1-0 counts, 2-0 counts and 2-1 counts against LHB. Blanton is basically pitching backwards here. Counts where he'd normally have to bring the fastball, you've got about a 50-50 shot on 1-0 and 2-0 and, on 2-1, it's only 1/3 fastballs. The result, here, is that he is often able to get weakly hit outs (he's managed a ~ .100 ISO in '07 and '08 with the pitch) or, also importantly, yet another pitch in a more favorable count. It's safe to say that the change is his most important pitch for getting lefties out. And it mostly works. BP's projected RHB/LHB split is .264/.319/.402 vs..271/.341/.410. The difference in the projected walk rate is notable, but it hasn't come to fruition.
Against RHB, he's a fastball-curve-slider pitcher and it's all about his curve. While the BABIP on pitches is going to take a while to come to rest at a reasonable rate, the ISO is no joke. It's 0 so far and last year it was .143. In other words, this is how Blanton gets his groundballs. It isn't on his meh fastball, with a .247 ISO to RHB, nor is it on the slider, which has little going for it. It's telling, I think, that he throws the slider for so few strikes and he's still giving up a .223 ISO on the pitch. His confidence in the pitch is apparently low; the usage rate dips significantly once he gets into 2+ ball counts. And it makes sense, it's a hittable pitch. That's usually not something you want to throw while behind.
So what's the approach? For RHB, you must (MUST!) lay off the curve. No good will come from swinging at it. It's better to think of it as an outstanding sinker. Unless it's elevated and you've seen it already and you as a hitter have some aptitude for hitting curves, don't touch it. The fastball and slider, OTOH, are very hittable. The key is to get the right one. He doesn't nibble with the fastball and without the luxury of the changeup, it comes more or less undisguised.
LHB have their work cut out. The fastball is imminently crushable and if it's on the inner half, it's probably a fastball. With a change up pitcher, I think it's best in the first time through to try to go the other way and cover the plate while seeing as many pitches as you can. I think this is the best way to convince the opposing pitcher to try to get back inside and, hopefully, abandon the change a bit as a result. For once (and this will no doubt screw him), I like AJ's chances. He's great at going to the opposite field and his open stance, I think, allows him to recognize the change up better. Thome has a chance to do well; he's already hit 3 HR on change ups this year.
Given the run scoring environment, I like our chances to put up a crooked number against Blanton. He's a smart pitcher and should be fun to watch because of it, but he's the kind of guy who's going to thrive with Oakland's pitching-and-defense oriented team and ballpark. Because of the sheer number of batted balls he allows, in the Cell, this is a backwards approach. Lay off the curve and he's got plenty of pitches that White Sox hitters can put loft on.