Let's look at this again. In my mind, there are 3 primary competitors (not counting Rivera):
Sabathia, Verlander, Hernandez.
Assuming Greinke keeps his ERA around 2.25, and gets his win total to, say 16-8 or even 16-9, here's what we need to root for:
Sabathia currently has 17 wins, but, AND THIS IS CRUCIAL, most likely has only 3 starts left. (19th, 24th, 29th, then they would likely skip him the last weekend so he could start the playoff opener). If he falls short of the magical 20 win figure, then Greinke could beat him out.
Verlander currently has 16 wins, but like Sabathia, most likely has only 3 starts left, IF, AND THIS IS A BIG IF, Detroit can clinch it before the last weekend. (Verlander pitches on the 19th, 24th, 29th, then skipped on the weekend so he could open the playoffs). Bottom line - no way Verlander gets to 20 wins.
King Felix - currently has 15 wins, and like Greinke will only get 4 more starts. (18th, 23rd, 28th, Oct 3rd). Can't get to 20 wins either, but we really need him to stay only 1 or 2 wins ahead of Greinke, and for Zack to maintain his current ERA gap over Hernandez of about a third of a run or so.
Looking at the schedule, it may come down to THE ROYALS HITTERS, who may need to get Sabathia a ND or a loss in his last start, which looks like it will be against KC.
You will note I'm discounting the voters doing something idiotic like give it to Rivera as some sort of career achievement award. I may be making a big mistake discounting this - but I'm hopeful the voters are sufficiently more informed now than they have been in the past.