Deriving Intrinsic Baseball Pitcher Value By Predicting Pitcher Performance From Individual Pitch Metrics

Historically, the predominant strategy for evaluating baseball pitchers has been through statistics created directly from the offensive production against the pitcher, such as ERA. Such statistics are inherently relative to the abilities and competition level of the opposing offense and the field defense, which the pitcher has no control over, making it difficult to compare pitchers across leagues. In this paper, I use cutting edge pitch-tracking data to develop a pitch evaluation model that is intrinsic to the attributes of the pitches themselves, and not influenced directly by the outcomes of each individual pitch. I train four different classifiers to predict the probability of each pitch belonging to different subsets of outcomes, then multiply the probability of each outcome by that outcome’s average run value to arrive at an expected run value for the pitch. I compare the performance of each classifier to a baseline, examine the most impactful features, and compare the top pitchers identified by the model to those identified by a different baseball statistics resource, ultimately concluding that three of the four classification models are productive and that the overall intrinsic evaluation model accurately identifies the sports top performers.