Matt Cain ignores xFIP, again and again

Matt Cain is pretty darn good, I mean, right?

Bill at Crashburn Alley doesn't think so. He recently said Cain "... may be one of the most overrated pitchers in baseball (though you can’t fault him for pitching to the strengths of his home ballpark)..." Is this true? It wasn't just Crashburn Alley that brought about this post; Cain's worth is bandied about constantly, at least in my experience.

If we're to simply look at his FIP and xFIP, a lot of people would say Cain has been lucky. Really lucky. Boy, he's been lucky with that home rune rate, it must be because he pitches at AT&T. Boy, he's been lucky with his batting average on balls in play (BABiP). It must be because of spacious AT&T.

Cain made his debut in 2005, but his first full season didn't come until 2006, when he'd throw 190.2 innings. He'd arrived. All said and done, he posted a 3.5 WAR (Wins Above Replacement) and finished with a 4.15 ERA and 13 wins. His FIP (fielding independent pitching) was 3.96 but his xFIP (adjusted FIP that pushes the home run per fly ball (HR/FB) rate to league average) was just 4.54. Perhaps it was just beginners luck.