ONE Championship and PFL: how they really differ from the UFC

You watch a bout, one fighter is down on the canvas, the other knees him in the head — and the referee waves it on. Or you read that someone banked a million dollars across six months of fighting and has never set foot in the UFC. If you learned MMA through the UFC, your first ONE Championship or PFL card feels like a related but distinctly different sport.

The core is actually shared. All three use 4oz gloves, five-minute rounds, three rounds for a normal bout and five for a main event. The differences sit in three places: what is legal inside the cage, how a fight is scored, and how you get booked in the first place.

The UFC as the baseline

The UFC runs on the Unified Rules of MMA, the rulebook adopted by the American athletic commissions. Judges score each round separately on a 10-9 basis, which means you can lose two rounds badly and still win the fight by taking three close ones.

Weigh-ins happen the day before, with a 0.45kg allowance for non-title bouts, leaving roughly 30 hours to put fluid and food back on. Bookings are discretionary: matchmakers pair fighters using rankings, drawing power and calendar gaps, with no season and no league table. That route to a belt is broken down in our piece on how the UFC actually works.

ONE Championship: a different scale and a different rulebook

ONE was founded in Singapore in 2011 and keeps several sports under one roof: MMA, Muay Thai, kickboxing and submission grappling. The same athlete can fight MMA one month and Muay Thai the next — in small MMA gloves, over three three-minute rounds, which is a far sharper and more dangerous rhythm than traditional Muay Thai in big gloves.

The MMA rules are broader than the Unified Rules. Kicks and knees to the head of a grounded opponent are legal, which the American rulebook explicitly forbids. The practical effect is that lying on your back and waiting for a stand-up simply is not an option.

The biggest departure, though, is the weight process. After a death caused by dehydration in 2015, ONE scrapped conventional water cutting: athletes report their bodyweight regularly, get checked several times during fight week, and must pass a hydration test before the bout is sanctioned. Fail it and you come off the card, which bites harder than the usual percentage-of-purse fine. We covered why the old approach is risky in our article on cutting weight before a weigh-in.

To make that workable, the divisions are shifted upwards. ONE's strawweight limit is 56.7kg, which is exactly the UFC's flyweight. A fighter who would be a 61.2kg bantamweight in the UFC competes as a ONE flyweight. The division name sounds lighter, but the humans in it are much the same size — minus the ten kilos of water that get stripped off and poured back on.

Scoring differs too. ONE's judges assess the contest as a whole rather than round by round, looking first at how close the fight came to ending — knockout or submission — then at damage, then at the quality of the striking and grappling. A round won by holding someone against the fence counts for little if your opponent had a choke locked in two minutes later.

PFL: a season, a table and points

PFL emerged in 2018 out of World Series of Fighting and borrowed the logic of team sport: a regular season, a standings table, playoffs and a final. In the classic format a fighter has two regular-season bouts, the top point-scorers advance, and the winner of each division collects a million dollars.

The points are the whole idea. A win is worth 3, and a finish adds more: +3 in round one, +2 in round two, +1 in round three. So a decision win is 3 points and a first-round knockout is 6. Grinding out a safe decision can cost you a playoff spot, so fighters take risks earlier than they otherwise would.

The rulebook itself matches the UFC — Unified Rules, round-by-round scoring, day-before weigh-ins. The difference is purely structural. PFL bought Bellator in 2023 and launched regional leagues, so it now mixes season, tournament and one-off formats, but the points table remains its signature.

What this changes in camp

A season means peaking two or three times across six to eight months instead of once every three or four. Camps get shorter, total training volume comes down, and the gaps between bouts go on recovery and patching up small injuries rather than adding new skills.

Finish bonuses also shape tactics. Round one is fought more aggressively than would be sensible in a system that counts only wins and losses, but the aerobic base cannot be traded away — if the finish does not arrive, you still need a tank that lasts five rounds.

In ONE, weight management starts in the kitchen rather than the sauna. Without water cutting, a fighter sits 2-4kg above the limit year-round and comes down through food over several weeks. Strength and explosiveness hold up better, because nobody walks into the cage a day after shedding five litres of fluid.

Grappling is learned differently under different rules. If your opponent may kick you while you are on your back, playing guard becomes expensive, so the work shifts towards standing up, never ending up underneath, and controlling from the top. It is one reason a wrestling base is worth even more under that rulebook than it already is.

Common misconceptions

• ONE's rules are barbaric. Head strikes on the ground are genuinely more dangerous than the Unified Rules allow, but ONE is also the strictest on dehydration, which harms far more fighters than any single technique.
• Nobody cuts weight in ONE. They do — through food and time rather than water and a sweat suit.
• Everyone in PFL earns a million. One fighter per division per season does; the rest are on standard per-bout purses.
• A different format means a weaker level. The level depends on who signs, not on whether the promotion keeps a table.
• Whole-fight scoring ends bad decisions. It does not; it just moves the argument from a single round to the whole contest, as we explain in the piece on how MMA fights are scored.

When to see a doctor

If you spar at all, two signals are not for waiting out. The first is your head: a headache that persists for days after taking shots, nausea, blurred vision, balance problems, or training partners telling you that you seem slowed down.

The second is weight: dizziness on standing, cramping, very dark urine or not passing urine at all after a hard cut. Both warrant a proper assessment rather than a couple of rest days.

In short

• The shared core: 4oz gloves, five-minute rounds, three or five of them.
• ONE allows kicks and knees to a grounded head, scores the fight as a whole, and bans water cutting with mandatory hydration testing — which is why its divisions sit heavier than the names suggest.
• PFL uses the standard rulebook but adds a season and points: 3 for a win, plus 3, 2 or 1 for a finish in rounds one, two or three.
• The UFC stays a discretionary system of rankings and negotiated matchups with no season.
• For the fighter, that means a different camp rhythm, a different appetite for first-round risk, and a very different relationship with the scales.