Remember when baseball was boring? This was a grave concern, not long ago. If one wanted to bash Major League Baseball, the easiest button to push was its alleged boringness: How the game’s analytic and strategic evolutions had conspired to make nine innings an increasingly unwatchable endeavor. If you wished to be fancy, you could layer a cultural point on top, arguing that baseball’s languid pace was out of sync with need-it-now modern life, and, because of this, it was losing younger eyeballs. MLB was introducing new wrinkles, but it was probably too late. Nobody was talking about baseball. It was dull, dull, dull—a...