Actually, his lower GB% in AAA can be largely discounted. What you fail to note is the fact that his IFB% has jumped from 3.3% in AA to 10.7% in AAA. Also, his LD% has dropped slightly, while his H/9 has gone down to 7.37 from 7.71, year-over-year. BA slightly lower, WHIP slightly lower. In short, he's being hit less hard in AAA, than in AA. That leaves the control issue, some of which can be discounted, based on reports of Meyer's ongoing experiments with trying out a new pitch, and the ever-ongoing adjustments in his mechanics, which based on the history of tall pitchers, is likely to continue well into his late 20s or longer.