Professional Baseball Pitchers Drafted at a Younger Age Pitch More Innings During Their Professional Baseball Careers Than Pitchers Drafted at an Older Age

PURPOSE: To evaluate and describe the differences in characteristics between the Major League Baseball (MLB) pitchers with greater workload and career longevity in terms of innings pitched (IP) and performance-matched controls who have not experienced similar length careers. METHODS: Using publicly available data, we identified the top 100 MLB pitchers in terms of career IP. Controls were matched to the top 100 pitchers by draft year and round. Pitchers with fewer than 400 IP were excluded. Demographic information, performance statistics, and injury history were reviewed. Logistic regression analysis and Mann–Whitney U tests were used to compare data. RESULTS: Compared with controls, the top 100 pitchers in terms of IP were drafted at a younger age (19.35 vs 19.83, P < .001) and in later rounds (6.16 vs 2.45, P < .001). They made their MLB debut at a younger age (21.77 vs 23.12, P < .001). They also pitched fewer innings before debut (470.59 vs 632.07, P = .007), were older at their first (30.72 vs 27.50 years, P < .001) and second (32.42 vs 29.43 years, P < .001) designations to the injured list (IL), and had a significantly longer time from debut to first (3063.50 vs 1565.59 days, P < .001) and second (3712.10 vs 2202.03 days, P < .001) IL trips. The top 100 pitchers were 7.45 times less likely to have made a trip to the IL within 8 seasons from their debut and were 4.04 times more likely to be younger than 24 years at their major league debut. CONCLUSIONS: Pitchers with the greatest number of IP in their MLB careers were significantly younger when drafted and when they made their major league debut, although this age difference is likely clinically insignificant. Pitchers who were drafted or debuted at a later age accumulate more pre-debut innings and this may contribute to fewer total IP in the MLB. Similarly, later trips to the injured list and longer duration from debut to first or second trip to the IL, but not total IL trips, are predictive of longer careers compared to age and draft class matched controls. LEVEL OF EVIDENCE: III, retrospective cohort study.