You only need to have seen a few UFC pay-per-views to know the rules and judging criteria off by heart. Jon Anik and even Mike Goldberg reading them out at the start of every event is a classic piece of every fight card.
UFC fights are scored by three judges who use the 10-point must system, a scoring system brought over from boxing. The winner of the round receives 10 points, their opponent receiving 9 or less. Judges score based on effective striking and grappling, effective aggressiveness, and fighting area control, also known as octagon control.
In terms of things that are not allowed, the list is fairly large. Perhaps that’s a surprise to people that have seen some of the more gruesome elements of the sport, but it’s true. UFC fighters cannot partake in the following: headbutting, eye-gouging, biting, spitting, fish hooking, hair pulling, pile-driving, striking to the back of the head, striking the throat, extending the fingers towards the eyes, downward-pointing elbows, strike the groin, kicking or kneeing the head of a grounded opponent, stomping a grounded fighter, holding an opponent’s gloves or shorts, holding the fence, small joint manipulation, throwing an opponent outside of the fighting area, intentionally placing a finger into any orifice, cut or laceration, clawing, pinching or twisting the flesh, timidity, abusive language in the fighting area, disregard a referee’s instructions, unsportsmanlike conduct that results in injury, attacking an opponent after the period of combat, attacking an opponent during the break, attacking an opponent under the care of the referee and interference from the corner.
ONE Championship differs from the UFC massively in terms of the judging criteria it utilizes. Just like Pride FC did back in the day, in ONE Championship, judges score fights as a whole and not round by round. For casual fans who only know the biggest boxing and UFC fights, perhaps that concept is hard to wrap your head around, but there’s a very strong argument that it’s the better way to do things. When Max Holloway and Alexander Volkanovski fought their rematch last year, it was argued that a change needed to be made to the judging and this was one of the suggestions.
Judges score ONE fights based on whether there was a knockdown or near submission, then on internal or accumulated damage done, then on striking combinations and ground control, then on completed or defended takedowns and finally on effective aggression.
In terms of its ruleset, unlike the UFC, ONE Championship does not adopt the unified rules of MMA. However, this doesn’t mean that it’s the wild west of MMA. Generally, you can and can’t do the same things over in ONE as in the UFC. The main difference is something we saw come into play at ONE’s big event earlier this month, where Demetrious Johnson fought Adriano Moraes. In ONE, you’re allowed to throw knees at a grounded opponent, and of course, DJ suffered his first-ever KO loss to a knee while he was grounded in the title fight.