One afternoon in May, Diamondbacks third baseman Jake Lamb was engrossed in his daily pregame routine inside the clubhouse when he stopped, suddenly, in front of a TV screen. He had overheard an unlikely topic of conversation on the afternoon MLB Network show: a somewhat obscure second-year player on a middling team who was a having an unremarkable season. The talking heads were diving into a list of players whose average exit velocity—the speed at which a ball comes off a bat—had improved the most from the 2015 season, and they were discussing the hitter who'd seen the greatest jump.
The Metrics System: How MLB's Statcast is creating baseball's new arms race
