When Pat Gillick traded prospects Adrian Cardenas and Josh Outman to the A's for Joe Blanton in July 2008, most of us here were less than thrilled. Blanton was competent, but no better than that. He'd averaged only 5.1 K/9 over his career, and his ERA was sure to take a big tumble once he moved from the spacious McAfee Coliseum to our ridiculous bandbox here in Philadelphia. He was already almost 28 and unlikely to improve a whole lot more.
But then a funny thing (or actually, several funny things) happened along the way. Blanton's K rate has surprisingly been much better as a member of the Phillies than it ever was in Oakland. On the other hand, his HR/FB has been a lot worse since the trade, which might have been foreseeable if Citizens Bank Park had continued to play like a bandbox - except that Citizens Bank Park stopped playing like a bandbox at the same time. Overall, Blanton has gradually turned into a pitcher whose peripherals and DIPS have been much better than his actual in-game results indicate - which is, in essence, the exact opposite of what he'd been with Oakland. There was also a World Series home run mixed in there somewhere.
All in all, despite the high HR/FB, trading for Blanton has worked out pretty well for the Phillies so far. Projecting what he'll do in 2012 is difficult, though, for a number of reasons. (1) Blanton missed over two thirds of the 2011 season with elbow pain. There was no structural damage and no surgery was required, but it still makes him a question mark until further notice. (2) There are all kinds of trade rumors swirling around him - more on this below. (3) His pitch assortment has evolved quite a bit over the last couple of years and may still be in flux - more on this at this link from last May. (4) He's just been tough to figure out for his entire career. Check this out:
Look at those last three columns in particular. If you can identify a pattern out of that mess, let me know. Blanton's pitched seven full seasons in the big leagues, and his ERA, FIP, and xFIP have been aligned with each other only once. That's strange.
In the end, evaluating Blanton just comes down to an exercise in how much you really believe in orthodox sabermetric principles even in the face of two years worth of stats that appear to defy them. The sabermetric literature tells us that past xFIP is a better predictor of future ERA than either past ERA or past FIP are, and that pitchers' HR/FB rates and BABIPs are mostly (though not completely) based on luck and tend to gravitate toward the league average over the long run. Do you really believe that? If so, then drawing a conclusion from the data is pretty straightforward. Blanton has posted an xFIP- of ~95 over the past three years, ~99 over the past four years, and ~96 over the past five years. He is a solidly above-average pitcher and, if healthy, should earn every one of the 8.5 million dollars he's set to make in 2012, and more.
Will he get the opportunity to prove that in Philadelphia? It's unclear at this point. There's a possibility that the Phillies will run into some luxury tax problems this year, and generally speaking, if you absolutely must cut payroll, the back of the starting rotation is one of the more sensible places to look to do it. That doesn't mean it's always a good idea to look there, though.
In this case, I think it would be a positively bad idea to balance the books on Blanton's back, at least for the time being. There's no such thing as an untouchable - anyone can be traded if the return is good enough - and even if there were such a thing, Blanton certainly wouldn't qualify. But right now, he's undervalued, mainly because his unlucky HR/FBs and (sometimes) BABIPs in recent years have prevented his ERAs and win totals from accurately reflecting the quality of his performance. When it comes to making trades, the name of the game is to buy low and sell high, not the other way around. Blanton can be as expendable as the day is long, but even trade offers for expendable players should be refused if you're not going to get fair value for them in return. Just let Joe eat his innings and enjoy the results.