As fans return to ballparks in droves, they can take in the traditional sounds of America’s pastime: the crack of the bat, the pop of the glove, the roar of the crowd. Over the past two years, though, the people in dugouts have begun to report a different noise: that of baseballs tearing off the hands of the pitchers throwing them. As the league reckons with existential questions about its future, perhaps the most important topic is this sticky situation.