This study aims to identify factors influencing the success of sacrifice flies in US Major League Baseball. From baseball-tracking outputs of official games during 2023–2024, 3439 flyouts reaching >50 m from home plate when a runner was on third base with <2 outs were analyzed. A multiclass classification model was developed to predict results of runners at third base (i.e., stayed at third base, tagged out at home plate, or scored on a sacrifice fly) from batted ball kinematics, runner's sprint speed (SS), the fielder's arm strength (AS), and ballpark. Average probability scores were compared by systematically altering these inputs. The results show that (i) the model accurately predicted the runner staying at third and sacrifice flies (F-score ≥ 0.842) but could not predict tag outs (0.057), (ii) nearly all flyouts reaching <70 m from home plate would result in the runner staying on third base, whereas the runner usually would score when the flyouts reach ≥85 m, and (iii) the shortest flight distance required for a sacrifice fly could be expressed by a simplified linear function: distance = 87.2–3.1SS + 0.7AS. This function will help set targets for better decision-making and greater success of sacrifice flies.
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