Boxing is a contact sport, single combat, in which athletes strike each other with their fists in special gloves. The referee controls the fight, which lasts up to 12 rounds. Victory is awarded if the opponent is knocked down and cannot rise within ten seconds (knockout) or if he is injured and does not allow him to continue the fight (technical knockout). If after a set number of rounds the bout has not been stopped, the winner is determined by the judges' scores.