One of the saddest things about having been born too soon is that by the time no-rules fighting came along, I was hopelessly old, sick and damaged. Sure, there were various martial arts when I was young. I tried the most popular, karate-only to discover it had more in common with ballet school than fighting. They didnt do full contact in standard karate classes back then. You were supposed to pull your punches and kicks, so you never found out if you could hurt anyone or not. Bart Simpson said it all in the episode where he pretends to go to the Malls karate dojo, reacting to Senseis claptrap about inner peace by saying, Dude, I already know how not to hit a guy.
Fiction came before fact in the genesis of no-rules tournaments. Long before real full-contact inter-style competitions began, dozens of Hong Kong movies focused on imaginary secret tournaments in which fighters of different styles were lured to the mysterious East and forced to fight each other to the death: sumo vs. karate, judo vs. kickboxing, boxers against capoeira masters, aikido gurus against wrestlers. Despite the fact that every one of these movies made money from the hordes of dreaming nerds around the world, it wasnt till the late eighties some entrepreneur in the US got the obvious idea of doing one of those tournaments for real.