No contest decisions in mixed martial arts (MMA) are usually declared when an accidental illegal strike (the rules on which differ from each organization) causes the recipient of the blow to be unable to continue, that decision being made by the referee, doctor, the fighter or his corner.
One common scenario leading to a no-contest is the occurrence of an accidental illegal strike resulting in injury. In such cases, neither fighter is declared the winner, and the bout is called off.