Boxing is sport that involves two opponents. When the opponents step into the boxing ring they agree to fight, following the regulations and rules of the sport. Participants are classified by weight, so that one opponent does not have a big advantage over the other. The weight limitations may be waived if both boxers agree to this condition. Spectators are placed around the boxing ring in order to watch the fight, and usually three judges score each round to determine who the winner is. The number of rounds fought can vary, depending on the condition of each opponent after each round