
In order to determine which is better, there needs to be a level playing field, something that doesn't currently exist. You see, for a traditional karateka to prove his training is better, he has to beat the sport martial artists at their own game. He has to enter an open tournament, play by their rules and out-perform them. It can definitely be done, but at what cost? How much modification does he have to do to his art in order to do so? Doesn't that conformity already mean in that moment he's no longer performing traditional karate, but rather a version of it designed for sport? The reverse is true as well. For a NASKA competitor to do well at a WKF event, they have to play by their rules, and are therefore no longer performing sport karate.
This isn't a new concept, however. The entire existence of Judo can be attributed to this dilemma. Following the end of the Samurai era, where classical martial arts could be tested on the battlefield (although Japan had just come off a 250-year peace period, where it could be argued the devaluation of traditional arts as "combat-ready" had already begun), individual ryuha began competing with one another. When Kano Jigoro burst onto the scene in 1882, naturally his goal was to prove that his new art of Judo was better by implementing a new form competition. So what did he do? He invited all of the classical arts to send their best fighters in order to compete in a friendly match, that he got to pick the rules for. Not only that, he stacked the deck by enlisting Saigo Shiro, adopted son of Saigo Tanomo (instructor to Daito Ryu's Takeda Sokaku), to be his prized fighter (read more about this by clicking here). So in essence, he used classical jujutsu to prove that Judo was better than classical jujutsu in a Judo-style tournament. Yeah, that makes my head hurt too.
Let's extend that to the debate between RBSD and MMA...