PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractThe usage of relief pitchers in Major League Baseball has been growing rapidly since the late 1970’s, but relief pitchers’ salaries have continued to be the lowest of any position group. This study investigates the importance of relief pitchers for MLB teams and how it has changed over time. This was done by creating linear regression models to assess the relationships between relief pitching performance metrics and teams’ performance, allowing us to determine if each metric is significant, as well as how it impacts team performance. First, the relationships between the relief pitching metrics and teams’ performance relative to their expected winning percentage were investigated, then the relationships between the relief pitching metrics and teams’ raw winning percentage were analyzed as well. There were no meaningful relationships found between any relief pitching metrics and teams’ performance relative to the expected winning percentage, but relief pitching depth was found to be the most significant predictor of teams’ raw winning percentage of the metrics that were tested. This indicates that when MLB general managers are building their rosters, quality of depth in relief pitching should take a higher priority than bringing in a star. Additionally, it was found that increasing the quality of relief pitching depth tends to increase team wins at a rate of 6 additional wins for every 0.5 decrease in average runs allowed per nine innings, further highlighting the importance of quality relief pitching depth in the modern MLB.
Degree ProgramStatistics and Data Science