The Pine Tar Incident occurred on July 24, 1983 when a rookie umpire made a highly controversial call about batter George Brett's use of pine tar on his bat's grip. The call resulted in the revocation of a home run that Brett had scored, causing Brett to lose his temper and run out of the dugout to confront the umpire, Tim McClelland. This was just one element in a dramatic scene that also saw one of Brett's teammates attempting to hide the offending bat.

At the time, Major League Baseball had official rules that limited how far up the bat a player could place pine tar, which helps improve grip. Brett's team, the Kansas City Royals, protested this call, and after examination and consideration from Major League Baseball officials, the call was reversed and Brett's home run was restored. The officials argued that, while the letter of the rule had been violated, its spirit had not. The pine tar rule was not imposed in order to prevent batters from getting a better grip on their bats but rather to prevent the tar from getting on baseballs, which would be quickly ruined upon repeated contact with pine tar. The rule, apparently, is more economical than ethical.