Offensive performance in baseball depends on a number of correlated factors: the pitches the batter faces, the batter’s choice to swing, and the batter’s hitting ability. The choices of whether or not to swing, which can be  describe as plate discipline, has traditionally been summarized as the proportion of pitches inside and outside of the strike zone a player swings at; however, there have been few metrics proposed to assess the effect of plate discipline directly on batters’ outcomes.

This summer Dr. Laura Boehm Vock and Ashley Neuenfeldt developed a metric for plate discipline which examined the effect of plate discipline on batting outcomes, not just for a single pitch, but considered which strategy is optimal over an entire at-bat. Using a causal inference statistical framework, they were able to find a plate discipline strategy for each player that optimized on-base percentage (OBP), slugging (SLG), or on-base plus slugging (OPS). A useful metric for comparing players is then the ratio of their observed OBP, SLG or OPS to the optimal. They examined trends related to this ratio. 

This research was made possible by The Presidential Faculty-Student Collaboration Grant