Major League Baseball is experiencing a new fan phenomenon called "Tarps Off," where groups, primarily of young men, remove their shirts and twirl them above their heads in stadium sections. This trend, often accompanied by soccer-like chants, is injecting new energy into games and is credited with contributing to increased attendance across the league.

The trend began at Busch Stadium in St. Louis on a Friday, when a club baseball team from Stephen F. Austin State University, in town for a tournament in Illinois, attended a Cardinals game. Seventeen players from the team initiated the shirtless cheering, and dozens of other fans quickly joined in. The Cardinals manager, Oliver Marmol, was so impressed by the energy that he purchased tickets for the group for the following day's game, and the team subsequently secured walk-off victories in both games where the "Tarps Off" fans were present.

Since its origin in St. Louis, the "Tarps Off" trend has spread to other MLB ballparks, including those in Detroit, Tampa Bay, Philadelphia, Seattle, and Anaheim. The phenomenon has been noted to create a college-like atmosphere and has been publicly acknowledged by players like Cardinals shortstop Masyn Winn. MLB is likely welcoming the attention, as attendance is up by approximately 1,000 fans per game compared to last year, with the league potentially averaging 30,000 fans per game for the first time since 2016 if the trend continues.