I'm not in a place to get screen grabs/make gifs, but I've been noticing Clay dipping his throwing arm lower than usual this year. He's always had a very heavy arm dip with both his windup and stretch deliveries, but it seems exaggerated as of late. Sometimes he also seems to have a deeper backleg/right knee dip.
This would have the affect of his arm not being able to come to a proper release point, and the ball staying up in the zone, and breaking pitches staying much flatter (along with a dip in velocity). Now, it's not SO bad that he's pulling any Rick Ankiel's, but it could explain why, when he looks generally steady, mechanics wise, start to start and season to season, there's been very, very different results.