During the Sinquefield Cup in September 2022, a controversy arose involving the chess grandmasters Magnus Carlsen, then world champion, and Hans Niemann. Carlsen, after surprisingly losing in their third-round matchup, dropped out of the tournament. Many interpreted his withdrawal as Carlsen tacitly accusing Niemann of having cheated. In their next tournament meetup, an online tournament, Carlsen abruptly resigned after one move, perplexing observers again. It became the most serious scandal about cheating allegations in chess in years, and it garnered significant attention in the news media worldwide.

The Sinquefield Cup is an annual, closed chess tournament in St. Louis, Missouri, United States, honoring Rex Sinquefield and his wife Jeanne, the founders of the Saint Louis Chess Club. Since 2015, the Sinquefield Cup has been a part of the Grand Chess Tour.