As its name so wonderfully suggests, chessboxing is a hybrid sport that combines the physical exercise of boxing with the mental acuity of chess. It's a full-contact sport where opponents alternate between rounds of chess and boxing. The bout consists of up to 11 rounds: six of chess and five of boxing. The winner is determined by a checkmate in chess, a technical knockout in boxing, or a judge's decision.
Interestingly, the term 'chessboxing' originated from a 1979 martial arts movie and grew from there. While the first official chessboxing event took place in London, it's now spread worldwide, with the biggest competitions taking place in Los Angeles.