My son and I were talking about this last weekend. We like Sabermetrics (numbers in general a lot ;-) so I'm inclined to latch onto Fielding Independent Pitching (FIP) as the best metric to measure a pitcher. As noted in the article, it is used a lot by FanGraphs. I'm constantly looking at FanGraphs and Sabermetrics to fully understand all of their formulas and acronyms, but I think this one is pretty straight forward. JMO.
http://www.beyondtheboxscore.c...g-basic-sabermetrics