Overview
- The movement began at Busch Stadium during the weekend of May 15–16 when Stephen F. Austin club baseball players and other fans took off their shirts, waved them like rally towels and helped spark an extra‑inning surge for the Cardinals.
- St. Louis this week formally dedicated the upper right‑field bleachers as a high‑energy 'Tarps Off' section and Cardinals manager Oli Marmol publicly embraced the group by buying tickets and inviting members into the clubhouse.
- The trend has appeared at multiple parks including Tampa Bay, Detroit, Seattle, Philadelphia and Anaheim with players and coaches visibly reacting on the field and sometimes joining the roll‑call style chants.
- Several teams — notably the Red Sox — say there is no specific ban on removing shirts but have reminded fans to follow stadium codes of conduct as clubs monitor safety, decency and the risk of interfering with play.
- The craze traces to a college‑football phenomenon in 2025 and could boost attendance and atmosphere if it endures, though its spread will likely depend on local team policies, weather and how clubs handle conduct issues.