Technology adoption and bias in officiating: automated Ball-Strike System implementation in Korean Baseball

Research Question Officiating technologies are increasingly gaining attention in sports leagues as a means to reduce the subjectivity inherent in human umpire decision-making. In 2024, the Korea Baseball Organization (KBO) officially implemented the Automated Ball-Strike System (ABS), which utilizes advanced technology to determine ball-strike decisions. This technological advancement holds the potential to eliminate preexisting biases in ball-strike decisions, particularly those favoring prominent players. Treating this policy change as a natural experiment, we examine whether ABS adoption differentially affects players’ performance based on status.Research Methods Utilizing data from the 2023 and 2024 KBO seasons (n = 148 for batters; n = 112 for pitchers), we estimate a series of difference-in-differences linear regressions to identify the impact of ABS adoption.Results and Findings We find that ABS negatively affects high-status batters’ performance – particularly OBP, IsoD, BB%, SO%, and BB/K – relative to low-status batters. In contrast, high-status pitchers’ performance remains unaffected.Implications Our findings not only inform sports leagues about the unintended effects of technological adoption in officiating but also offer broader insights for labor markets where subjective evaluation remains prevalent.