Unanimous decision

A unanimous decision (UD) is a winning criterion in several full-contact combat sports, such as boxing, kickboxing, Muay Thai, mixed martial arts and other sports involving striking and submission in which all three judges agree on which fighter won the match.

In boxing, each of the three judges keeps score (round by round) of which fighter they feel is winning (and losing). This only includes landed blows to the head or the body. In MMA, judges look for different criteria such as kicks, take-downs, punches, knees, elbows, cage control, submission attempts, and aggression. A decision is not required to be unanimous for a boxer or mixed martial artist to be given a victory. In the modern era of Olympic boxing, UD is utilized more often than other outcomes, including stoppages. Unanimous decision should not be confused with a majority decision or split decision.

History
In the early days of combat fighting, winners were determined only when one party was unable to continue the fight. The National Sporting Club started to promote professional glove fighting. It introduced the use of officials and their capacity to declare the winner of a fight. Officials began using a scoring system to determine the winner of the fight, and this made unanimous decisions a logical outcome.

Any combat sports decision has the potential to be overturned. Some reasons for this may include counting errors, misdeclaration, and retroactive disqualification due to rule violations. There has never been a unanimous decision overturned.

Boxing

 * Floyd Mayweather Jr. - 20 wins by UD
 * Muhammad Ali - 18 wins by UD
 * Manny Pacquiao - 18 wins by UD
 * Joe Louis - 9 wins by UD

MMA

 * Jon Jones - 9 wins by UD
 * Anderson Silva - 9 wins by UD
 * Georges St-Pierre - 10 wins by UD
 * Kamaru Usman - 9 wins by UD