The precise rules of boxing in antiquity cannot be known for certain, and are thus inferred from historical references and images. It is believed that any type of blow with the hand was permitted, though using the hands to gouge at the eyeballs was not. Holding or wrestling one's opponent was also prohibited. If the fight lasted too long due to the tenacity of the competitors, the athletes could choose to exchange blows undefended to speed up the process. Judges probably enforced the rules by beating the offenders with a switch or a whip.