In MMA, you could also argue that both BJJ and especially Judo needs to be modified for sweaty, No-Gi action, so what we see in MMA is not the original martial arts. At the start of this thread, I was thinking of going "BJJ rulez da worlddd!!!", but now that I think of it several outstanding MMA fighters are primary Judo practitioners. But I still think even more fighters have BJJ background, statistically speaking.
But for instance Aoki is a BJJ fighter as well as a Judo fighter. And Fedor's style is obviously Sambo (but since the throws are similar he has been able to compete in Judo as well). I think that since Judo and BJJ are so similar, a good fighter needs to learn both.
But there's one difference: If say, a striker needs to learn how to not get killed on the ground, he wouldn't exactly go to a judo dojo and start to learn all throws and defenses with a gi. He'd start doing more wrestling and no-gi jiu jutsu. With that I mean people with Judo backgrounds seem to kick serious ass in MMA, it's perhaps not the best style to use to complete your game. At least not as far as I know.
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