Analyzing MLB 2-Pitch Sequences

Major League Baseball (MLB) batters face split-second decisions that can determine game outcomes, yet little research examines how consecutive pitch decisions influence each other. This analysis explores whether swinging at a first pitch affects decision quality on the second pitch. Using causal inference methods (i.e., propensity score matching, coarsened exact matching, and inverse propensity score weighting) on data from the 2023 MLB season, we account for various confounding factors including pitch location, velocity, and batter tendencies. The findings reveal that batters who swing at the first pitch make significantly better decisions on the following pitch compared to those who take the first pitch. While modest in magnitude, this finding suggests that aggressive first-pitch approaches may positively influence subsequent pitch decisions, potentially offering strategic insights for player development and in-game tactics.