PRECISE DATA FOR A SINGLE PITCH.

PRECISE DATA FOR A SINGLE PITCH. Alan Nathan’s analysis of the physics of a single pitch and line drive builds on an amazing amount of data that is now available for baseball games. Nathan knows that on the pitch that Hunter Pence hit, “… the initial batted ball speed was 76.8 mph, the vertical launch angle was 10.3o, and the horizontal spray angle was 19.0o to the left of the home plate-2B line.” He is also able to determine the amount of sideways movement provided by the strange impacts of the bat: “… the ball that started out at 19o to the left of 2B ends up hitting the ground 17o to the left of 2B, which corresponds to about 4 ft of break. That is, the landing point of the ball is 4 ft to [the shortstop’s] left of where it would have landed if it continued on its initial trajectory.” Nathan is also able to determine the expected sideways break of the ball because he has data available from other games: “For a ball hit at 19o to the left of 2B …, the average amount of break is about 2o to the left. The actual break was 2o to the right.” So a shortstop reacting to Pence’s line drive as if would break the way that similar line drives break would have been off by 8 feet. He also concludes that Pence’s batted ball had “560 rpm of sidespin causing it to slice and 200 rpm of topspin”.