This brief article estimates the effects of a rule change from the early days of professional basketball. The Mikan rule was intended to curb the offensive potency of tall players whose primary contribution to team output consisted of points scored close to the basket. The Mikan rule limited players’ ability to stand close to the basket, and hence made it more difficult for these players to score. However, the rule change did not account for strategic offsetting behavior—that defensive players’ optimal allocation of resources would change in response to the rule. I engage the literature on strategic offsetting behavior and estimate a two-way fixed effects model that strongly suggests the Mikan rule did not have its intended effect due to strategic offsetting behavior.