I'm one of those who believe an ERA explosion is waiting unless he can drastically improve his K rate. His underlying metrics point to a much higher ERA: 76 K in 218 IP is almost comically low, his 52 BB isn't particularly strong; and a 1.31 WHIP and 277 BAA are not the stuff of mid-3 ERAs.
He's allowing a fair number of baserunners and a TON of balls in play. So far, he has survived on the strength of his extremely high GB rate and luck that those GBs were playable. But anyone who allows that many balls put in play is "living on the edge" -- especially in the AL East, with more that its share of sluggers, and on the Yanks, which have had more than their share of defensive problems.
Unless he can materially improve that K rate, I think his ERA next year will be closer to the mid-4s than the mid-3s.
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