DANVILLE, Va. — For Chris Hervey, the crack of the bat was the first call to attention — a clarion that cut through a February day in Chicago to alert the Mets’ upper Midwest scout that this was a batting practice session worth watching.



Then he saw the smoothness of the left-handed swing, an ease of operation that struck him as natural and almost innate, as unconscious as walking down the street.



Finally, he checked his notes and shook his head.



“Dear God,” Hervey said to himself. “This guy is for next year’s class?”



That’s the day Hervey and the Mets fell for Jarred Kelenic.



In taking Kelenic sixth overall, the Mets went against a piece of their organizational philosophy. New York prefers the more conservative route of taking a college prospect in the first round, especially at the top of the draft — where the best college players are viewed as near-ready impact prospects and, by...