Sometimes the game just doesn't add up...maybe he's being propped up by stuff like a good defense, high PC catcher, pitcher's ballpark (I have no idea what Monterrey's effects are), but that stuff only goes so far. Based on his ratings, I would stash him in AAA and use him as injury insurance, because he really shouldn't be very good at all. I would expect his career ERA to be about a full run higher, and his run over the past 2.5 seasons is particularly inexplicable.