Intimidation, Discrimination, and Retaliation: Hit-by-Pitches during the Integration of Major League Baseball

During the first ten seasons of integrated Major League Baseball, black batters were hit by pitches about 86% more often per plate-appearance than white batters. However, on average black players during this period were superior players. To investigate to what extent the difference in hit-by-pitch can be explained by performance and characteristics other than race, we use a fractional logit model to estimate hit-by-pitch per plate appearance during a season. Our data are from Baseball-Reference.com. Controlling for differences in performance and other characteristics and including interaction terms with race, the difference falls to about 42%. A little over half the difference is explained by factors beyond race. The remaining difference might reflect different batting styles for early black batters. However, when observations where hit-by-pitch per plate appearance are in the top 2.5% of the sample are removed, black players were about 46% more likely to be hit. Plots of the marginal effects from a model using interactive terms show that the likelihood of a black player being hit rose relative to that of a white player as base-on-balls, singles, doubles, home runs, or stolen bases per plate appearance rose. Some pitchers may have exhibited animosity towards black players either by hitting them or taking less care to avoid hitting them. Our findings support previous research that better batters and batters who play for teams who score more runs are more likely to be hit by pitches. Because empirical evidence suggests pitchers might alter pitches to intimidate, discriminate, or retaliate, changes to existing rules could reduce the frequency of hits-by-pitch.