Minutes before the first Abu Dhabi Warriors Fighting Championships began on Friday night, the line that could decipher this sport to everyone came from Will Vanders, the energetic veteran mixed-martial arts (MMA) commentator.
"As a child," he said, "we'd always ask who would win a fight between Muhammad Ali and Bruce Lee. Well, in the MMA you can find out."
That sounds like a real seller. And, actually, in 1976, when Ali took on the Japanese professional wrestler Antonio Inoki in a fight under special rules, that idle fantasy first became reality. It was a farce, a drawn fight, and unwatchable, allowing both contestants debatable claims to victory.
Years later, that idle fantasy has become an organised sport, one that insiders regularly claim to be the fastest growing in the world.
That remains an untested claim (one made by many sports) because these things are difficult to measure. But the crowd turnout last night at least points to potentially mass appeal.
The 3,700-capacity Abu Dhabi National Exhibition Centre hall was more or less full and given the alternatives on offer this weekend - a Formula 1 weekend, remember, with big-time live music alternatives at Yas Island and Abu Dhabi Corniche - that was more than could have been expected. People it seems love a fight.
It is a sport but it is easy to overlook that because fight nights can be slick, choreographed productions.
The lasers and lights, the stage the fighters walk out on to, all manner of fit people pottering around busily, the very loud music and deep-throated MCs: this could be a fashion show or some extravagant spectacle of sound and light.
But once the fights began, there was no escaping the reality of what this is, though that is not what might be expected.
In the mind, the MMA is a brutal and bloody exercise, but on last night's evidence, it is an unwieldy kind of fighting, not always as violently or spectacularly abrupt. If anything, Vanders' Ali-and-Lee quip is a solid visual reference.
The range of styles - boxing, amateur wrestling, Brazilian ju-jitsu, judo, Muay Thai - can be disorienting.
In the night's first fight, between Flavio Serafim and Andrew Nicola, the pair grappled and grappled on the mat, became entangled in a ju-jitsu mess, leverage being sought, switching holds, until suddenly Serafin got his opponent into a submission hold you might have seen Chris Benoit, the late WWE wrestler, practice.
And then it was over, only three minutes into the first round, the words of referee John McCarthy as clear as day, that if you do not call off the fight quickly enough, real trouble is waiting.
Boxing provides a strong base as well, as was obvious in Magomed Magomedkerimov's win over the Brazilian Thiago Vella, who is based as a coach in the UAE. Magomedkerimov knocked down Vella thrice in the first and only round, the final right hook heard and felt far back in the stands.
First-round finishes for the first two fights, but so different in nature you could see why purists of various fight sports tut-tut at the mesh of styles MMA enforces. But at a very base level, how can you not respect - even if grudgingly - what these fighters go through?
MMA might not be pure, but here there could be no doubting how real it is.