Justin Antolin '21
Abstract
The frequency of TJS is on the rise among youth and professional baseball pitchers. Many of these players are receiving treatment preemptively, with the belief that the surgery will improve pitching performance. The purpose of this study is to determine the statistical significance of TJS on the overall performance of major league pitchers. Data on 13 carefully selected MLB pitchers were collected and analyzed. The average ERA, FIP, and WAR of each pitcher before their surgery was noted and then subtracted from the average ERA, FIP, and WAR of each player after their surgery. The weighted average and standard deviation of these differences was taken and recorded, and confidence intervals for each value were then computed (alpha= .05).
Introduction
The Ulnar Collateral Ligament (UCL) is the primary ligament in the elbow and receives the brunt of the stress during overhand throwing motions in sports like baseball, tennis, and football (quarterbacks) to name a few. In baseball, injury to the ligament is common in pitchers and often results in two treatment methods depending on the severity of the injury. One of these methods is simple rehabilitation through physical therapy and other gradual methods. The second method, which serves as the focus of this study, is Ulnar Collateral Ligament Reconstruction, or more colloquially referred to as Tommy John Surgery (TJS). The public stigma surrounding the procedure is not so simply understood. It is widely believed by many athletes, parents, and medical professionals that replacing the UCL at an early age, even without damage or fear of future damage, enhances load capacity, pitching speed, and overall pitching capability. This pattern has likely trickled down from the MLB level, where constant media downplay of the grueling recovery and future health risks has bred a more less cautious outlook. As Lansdown and Feeley note in their 2014 study in their Orthopedic Journal of Sports Medicine article, a six-fold increase in the frequency of TJS among high school pitchers was noted between 1995 and 2004. The trend has not slowed, as Conte and Hodgins cite in their 2015 study in The Physician and Sportsmedicine that more than 45% of media professionals did not think that previous injury needed to be a prerequisite for TJS. Further, they showed that less than half of all MLB players actually believed that measures like advanced pitch counts actually help prevent TJS. It is my belief that this public sentiment that Tommy John increases pitching viability is misguided and will lead to more unnecessary harm of pitchers, especially those in their youth.
Hypothesis
Overall pitching performance, as calculated by ERA, FIP, and WAR, significantly decreases following Ulnar Collateral Ligament Replacement.
Methods
Using available media resources, 179 pitchers were deemed as potential candidates for study, as they had undergone Tommy John surgery at some point in their professional career. After sorting out pitchers due to extenuating health circumstances that may have contributed to a decline in performance, a procedure that happened too early or late in a player’s career, or simply not having enough seasons with over 50 innings pitched, a final list of 13 pitchers was compiled. Using pitching data available on baseball-reference.com, each pitcher’s average ERA, FIP, and WAR each year were recorded. These categories were chosen to best reflect changes in pitcher value and overall performance. After finding each pitcher’s average ERA, FIP, and WAR both before their operation and after, the latter was subtracted from the former, and averages, standard deviations and confidence intervals were computed for each of these values. From here speculation could be made regarding the meaning of the results. A sample of the process used is shown:
Results
The large positive number for the average change in ERA suggests that after each pitcher underwent TJS, their ERA was likely to increase each subsequent year. The results are a little hazier for FIP, as the average change is only slightly positive, with a large degree of uncertainty. For WAR, the results are astonishingly supportive of the initial hypothesis, with a relatively large negative number signifying a solid decrease in WAR after each operation.
Discussion
While the data shown provides strong evidence that TJS decreases pitching performance, it is important to note that the methods used reflect a series of averages, and are not necessarily representative of each and every case. Similarly, the data were narrowed down to only 3 categories out of dozens of metrics by which pitchers are evaluated (pitch velocity, strikeouts, walks, etc.), possibly leading to some error. Perhaps future studies will include multiple other metrics in the analysis (most notably pitch velocity), and thus, possibly allow for the inclusion of more pitchers in the analysis.
Bibliography:
1. Lansdown, D., & Feeley, B. (2014). The Effect of Ulnar Collateral Ligament Reconstruction on Pitch Velocity in Major League Baseball Pitchers. Orthopaedic Journal of Sports Medicine,2(2). doi:10.1177 Conte, S., & Hodgins, J. (2015). Media perceptions of Tommy John surgery. The Physician and Sportsmedicine, 43(4). doi:10.1080
2. Baseball Reference