Pitch Metrics and the Trade-Offs Between Elbow Injury and Performance in Major League Baseball Pitchers
Jonathan S. Slowik, Dev Rupani, J. Bradford Hall, Jeffrey R. Dugas, Glenn S. FleisigBackground:
Elbow injuries among baseball pitchers continue to rise, with increasing emphasis on velocity, spin, and related pitch metrics as likely contributors. However, the trade-offs between performance and injury burden are not well understood.
Purpose:
To evaluate relationships between pitch metrics, elbow injury burden, and performance in Major League Baseball (MLB) pitchers, and to assess trade-offs between these outcomes.
Study Design:
Cross-sectional study.
Methods:
Publicly available pitch metrics, performance measures, and injury data were analyzed for MLB pitchers during the 2022 to 2025 regular seasons. Pitch metrics included velocity, spin rate, vertical and horizontal movement, release characteristics, pitch-type usage, and pitch quality models (Pitching+, Stuff+, and Location+). Pitch arsenal diversity was quantified using the effective number of pitch types (N eff ). Outcomes included elbow injury burden (days on the injured list due to elbow injuries [ElbowDays]), expected earned run average (xERA), and FanGraphs wins above replacement (fWAR). Regression models evaluated associations between pitch metrics and outcomes, adjusting for age, service time, and role (starter/reliever), with effects standardized per standard deviation.
Results:
Among 406 pitchers, velocity showed the most consistent effects. A 1-SD increase in average velocity was associated with 36% greater ElbowDays alongside improved performance (–4% xERA; +0.18 fWAR). Similar trade-offs were observed for 4-seam velocity, sinker velocity, and 4-seam Pitching+. Increased spin rate, induced vertical break, and arm angle were associated with increased ElbowDays but limited or inconsistent performance benefits. Greater arsenal diversity (N eff ) was associated with reduced ElbowDays (–26%) but slightly worse xERA (+4%) and no significant change in fWAR. Higher sinker usage was associated with reduced ElbowDays (–15%) without significant performance effects.
Conclusion:
Velocity, spin, and related metrics are associated with improved MLB pitching performance but increased elbow injury burden, indicating a measurable performance-injury trade-off. In contrast, greater arsenal diversity, increased sinker usage, and lower arm angle may improve durability with minimal performance cost. Future research examining the contextual components of pitch quality models beyond raw metrics is warranted.