I think all of us agree that Felix Hernandez has been the most outstanding pitcher in the American League, in terms of his results. He's #1 in innings and #1 in ERA, and though he's #5 in FIP and #3 in xFIP, he's thrown more than the guys in front of him, and his performance with men on base has to count for something. If I put up a poll asking the readers to pick their AL Cy Young, I imagine 99% of you would choose Felix.
Percent of same-handed batters faced:
Felix is right-handed. The other guys are left-handed. As you can imagine, it's a lot easier for a manager to stack his lineup against lefties than it is against righties.
And so, overall, Felix has worked from an advantageous position. Pitchers are better against same-handed hitters than opposite-handed hitters, and Felix has worked with the platoon advantage almost twice as often as his competitors.
Does this matter? How much does this matter?
On the one hand, we care about ease. If one guy throws a shutout against the, while another guy gives up a run against the , we'll give the edge to the second guy, because even though he had the slightly worse performance, he faced a much tougher challenge. It's something you adjust for. Ideally, the Cy Young voters would find a way to adjust for pitcher opponent to strip away any advantages or disadvantages.
On the other hand, being right-handed is just a natural advantage for Felix, the same way throwing a mid-90s fastball or dynamite breaking balls are natural advantages. Why should he be penalized for that? It's not like we adjust pitcher results based on their stuff. When we talk about the Cy Young, it's not like we regress guys' numbers to some hypothetical repertoire mean.
Which advantages matter, and which advantages don't?
Maybe it's right under my nose and I don't realize it, but I don't have the answer. Just something to think about as the season winds to a close.