Joe Blanton may not be an "ace" but he's a good pitcher who is sometimes underappreciated. We've spent a lot of time discussing this around these parts and there's no reason to beat that horse any further. One issue we haven't discussed as much, however, is how Blanton is so good. The answer to that question is less than obvious.
It's well known that although the ability to throw a 90 mph-or-better fastball is not a sufficient condition for succeeding as a major league pitcher, it's fairly close to being a necessary condition - at least for righties. Last year, there were only 20 RHP in MLB (min. 100 IP) whose fastballs were, on average, slower than 89.5 mph. Blanton just "made the cut" at 89.4 mph.
Only six of these guys were able to post xFIPs below 4.00 - Dickey, Marcum, Pineiro, Lowe, Myers, and Blanton. The median xFIP in MLB was 4.04.
How did they do it? Surprisingly, it wasn't really because of great control. All six certainly had good control, but only two were truly top-of-the-line in that department. Marcum had the 12th lowest walk rate among the 147 major league pitchers who exceeded 100 IP, while Pineiro was 15th.
Three of the six were groundball machines. Dickey was 10th in GB%, Pineiro was 11th, and Lowe was 3rd.
The other three all had very good strikeout rates notwithstanding their slow fastballs. Two of those three were helped by nasty secondary pitches. Marcum posted a whopping +26.0 on his wCH (that is, his "changeup runs above average") - the second straight year he's reached positive double digits with that pitch. Myers has reached positive double digits on his curveball four times in his career, including in 2010 (+13.2 wCB). He also did it with his slider in 2010 (+14.7 wSL), the first time he's managed that feat.
And that leaves Mr. Blanton. He was very good at limiting walks, but he wasn't inhuman at it (26th lowest walk rate). He was actually below the median at inducing grounders (93rd best GB%). And none of his secondary pitches were particularly impressive - the most effective of them being a cutter that he didn't even throw very frequently (2.4 wCT).
Basically, aside from the good walk rate, the reason for Blanton's success last year was that, despite having a slow fastball and a bunch of secondary pitches that aren't that great, he was somehow still able to strike people out at a rate that was well above average (36th in MLB). How? You'll have to tell me because I honestly don't know.