The Elo rating system is a method for calculating the relative skill levels of players in zero-sum games such as chess. It is named after its creator Arpad Elo, a Hungarian-American physics professor.

Chess boxing, or chessboxing, is a hybrid sport that combines two traditional disciplines: chess and boxing. Two combatants play alternating rounds of blitz chess and boxing until one wins by checkmate or knockout. It is also possible to win by time penalty as in normal chess, and by boxing decision if there is a draw in the chess round.