2024/09/05 by Sonia Markes, Markes, Sonia, Linbo Wang +5
Business, Management and Accounting · Economics, Econometrics and Finance · Social Sciences · #Applications (stat.AP) #FOS: Computer and information sciences #Sports Analytics and Performance #Transport and Economic Policies #Transportation Planning and Optimization
paper · pdf · doi:10.48550/arxiv.2409.03940
openalex publication_date 2024/09/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The infield shift has been increasingly used as a defensive strategy in baseball in recent years. Along with the upward trend in its usage, the notoriety of the shift has grown, as it is believed to be responsible for the recent decline in offence. In the 2023 season, Major League Baseball (MLB) implemented a rule change prohibiting the infield shift. However, there has been no systematic analysis of the effectiveness of infield shift to determine if it is a cause of the cooling in offence. We used publicly available data on MLB from 2015-2022 to evaluate the causal effect of the infield shift on the expected runs scored. We employed three methods for drawing causal conclusions from observational data -- nearest neighbour matching, inverse probability of treatment weighting, and instrumental variable analysis -- and evaluated the causal effect in subgroups defined by batter-handedness. The results of all methods showed the shift is effective at preventing runs, but primarily for left-handed batters.