This post by Dave Cameron at FanGraphs does a pretty good job at pointing out the difficulties that arise when trying to separate talent from results. Trevor Cahill has certainly had a very strong year by “traditional” measures (ERA, WHIP), but in other ways (GB%, K%) has performed worse than even
Jason Justin Masterson. I’m not very concerned about whether the Cy Young vote should be based on wins and losses or K-rate or SIERA (although if I did have a vote, it would probably be for Cliff Lee despite witnessing this in person). It’s not the perception of talent that I care about, but rather actual talent. More precisely, the probability that a particular player has talent level X on a given day (see here for a very good background). Using all of the wonderful information available from MLB.com, it is possible to begin stripping away park and luck and quality of opposition and come closer to some distribution of true talent level for that player.
However, of course a player doesn’t have just one talent – a pitcher might have great fastball velocity but no command, or a wonderful change but a curve that gets pounded. On the other end of the pitch, a hitter might crush high and tight fastballs from righties but couldn’t hit a curve from a lefty to save his life (and in the case of switch-hitters, they likely behave like two totally different hitters depending on the side of the plate they are on). My goal is to use what we do know based on what has happened in the past to construct a better measure of player talent.