Economists have debated whether and why the designated hitter (DH) rule in North American major league baseball led to an increase in hit-batsmen. We use data from Japan's professional baseball leagues, the Pacific League (DH rule) and the Central League (no DH rule), to re-examine this question. Our empirical findings reveal increases in hit-batsmen in the Pacific League after we control for the DH’s effect on team batting performance. We argue that the DH rule induced changes in managerial defensive strategies that led to more hit-batsmen. Subsequent rule changes reduced the effectiveness of these strategies.