Advanced Analytic and Pitch-Tracking Metrics Associated with UCL Surgery in Major League Baseball Pitchers: A Case-Control Study.

Background: Ulnar collateral ligament (UCL) injury rates have been rising steadily, while the recent development of advanced analytics and pitch-tracking analysis now drives player development and evaluation throughout Major League Baseball (MLB). Purpose: To evaluate the association between several advanced analytic and pitch-tracking metrics on UCL surgery rates in MLB pitchers. Study Design: Case-control study. Methods: Included in this study were MLB pitchers who underwent primary UCL reconstruction or repair from April 2018 to November 2023. Exclusion criteria were pitchers without 2 qualifying seasons of preoperative pitch-tracking data and those who previously underwent UCL surgery. Uninjured matched controls were identified in a 2:1 ratio using season, age, position, handedness, and pitch count as covariates. Advanced analytics (eg, FanGraphs wins above replacement [fWAR], expected fielding-independent pitching [xFIP], physical pitch qualities [Stuff+] strike-zone command [Location+], and overall pitching ability [Pitching+]) and various pitch-tracking metrics used commonly in MLB player evaluation were collected from public web sources sponsored by MLB and used in previous studies. Statistical analysis consisted of unpaired Results: A total of 117 MLB pitchers who underwent primary UCL reconstruction or repair were compared with 234 matched controls. Cases had significantly superior pitch velocity, fWAR, xFIP, Pitching+, and Location+ compared with controls. There was no significant difference between cases and controls in pitch counts, spin, release points, release extension, approach angles, or overall pitch movement. Binary logistic regression identified velocity, Pitching+, and decreased fastball usage as being associated with UCL surgery ( Conclusion: In this analysis of several modern advanced analytic and pitch-tracking metrics, MLB pitchers who underwent UCL surgery threw harder with less fastball usage, and had superior overall pitching ability (Pitching+) and strike-zone command (Location+) than matched controls.