although technique is vital to have in BJJ/MMA, imo brute strength n size helps out bigtime,providing the strong dude has some athletic ability n doesnt gas out in 30 seconds. i remember rolling with this guy named emmanuall yarborrough at cranford judo club, he was about 620 lbs back in 98 n it was pretty much impossible to tap him out, going for heel hooks was the only chance anyone had. u old school ufc guys prolly remember him, he got dropped by keith hackney with a open palm strike to head n was so big he couldnt get back to his feet once he was down n hackney was pounding on him from the back