Jonah Keri over at Grantland gives the 2015 NL Cy Young to Clayton Kershaw, a man who seems to be less commonly mentioned of late than teammate Zack Greinke or the Cubs' Jake Arrieta. Keri leans heavily upon Baseball Prospectus' Deserved Run Average (DRA) as the determining veriable, but it's still worth a read:
Baseball Prospectus combines DRA with innings pitched to calculate which pitchers delivered the most raw value. That combined stat is then scaled to look like the various derivations of Wins Above Replacement, where a 25th man would deliver a score around zero, an average player around two, an All-Star four or higher, and an elite player six or higher.