MLB sent out tacky balls for players to evaluate:

Rich Hill confirmed that the New York Mets reviewed the prototypes about a week-and-a-half ago. Los Angeles Dodgers pitchers were also shown the balls while playing in New York, and the San Francisco Giants are expected to receive them during their series against the Mets this week as well.

Spootrts.Yahoo.com

The trick will be to find a tackier ball that doesn’t increase spin. That’s been difficult so far, and MLB batters may need to accept some extra-spin to give the pitcher the grip they desire.