So yeah, this sport is pretty F’ing crazy. It’s called chess-boxing, and you can win either by checkmate or by knockout. Remind me never to sign up for this as I suck at boxing and chess equally. Thanks for the link Skitzzo.
"Two competitors face each other in 11 alternating rounds, six of chess,
five of boxing. A bout begins with chess, which is played on a board
placed directly in the middle of the ring. Each round of chess lasts
four minutes. After each chess round, the bell sounds, and workmen
remove the chessboard for a two-minute round of boxing, the gloves go
back on, the punching recommences. Participants win by way of knockout,
checkmate, referee’s decision…"