That makes sense Huge, for boxing. Floyd Mayweather/Pacquiao against even a decorated amateur would be dangerous for the amateur. for the martial arts guys, they'd be competing nationally to whittle down the participants to the squad who'll represent their country at the Olympics, so there should be a natural progression through the tiers of quality, though that won't be associated with belts/grades - I'd expect all international quality martial artists to have their black/'dan' grades - selection and match-making by belt/grade would usually be at club/inter-club level competition.