I think there's a chance JD opts out because of all the noise happening with the Sox these days, and all the rumors that he'll be traded if he doesn't opt out. He might prefer to control his own destiny even if it costs him a few mill.
One thing I did not realize until recently is that Bill James is not a proponent of using WAR to determine the MVP award. He came up with his own stat called Win Shares which is based on contributions to actual wins by the team.
As notin has suggested, what seems to be chocking by Verlander may actually be fatigue...
Maybe the Stros should have managed his innings a bit more this year.