“No grounders.” How Statcast data is revolutionizing Major League Baseball

Patrick Semansky, The Associated PressOne day several years ago, as Chase Headley was still trying to establish himself as the San Diego Padres’ everyday third baseman, Padres management passed around a sheet of paper full of facts and figures on how its spacious ballpark, Petco Park, played for hitters. Flyballs were mostly swallowed up in the vast expanses of outfield, while groundballs and line drives played better than in the average stadium. The conclusion, as Headley recalls it, was clear: Padres hitters should keep the ball out of the air.

“I had more loft in my swing when I came up,” Headley said recently, “so I was trying to undo some of that, and I was trying to hit the ball down.…