The 2021 pitch doctoring controversy arose in Major League Baseball (MLB) around pitchers' use of foreign substances, such as the resin-based Spider Tack, to improve their grip on the baseball and the spin rate on their pitches. On June 15, 2021, MLB announced a new policy whereby any player caught using foreign substances on baseballs would receive a 10-game suspension. The policy also included umpire inspections of all pitchers during games starting on June 21, a decision that was met with mixed reactions from players and coaches.