put it this way,floyd mayweather wouldnt last 30 seconds against bj penn,gomi ect in a mma match.mayweather would be subbed so quick he wouldnt even know what happened.rickson and rorion gracie both challenged tyson in 93 or so and tysons camp never responded,tysons camp knew they had everything to lose,tyson getting his ass kicked by a 175lb slim brazilian guy wouldnt be to good for tysons future,lol.boxers got destroyed in the earlier ufc,s against grapplers,just check the ufc fight stats.boxers are good at what they do but boxing is not an efficiant self defense art in combat,its great combined with bjj but by itself youll be in deep shit if a wrestler or bjj grabs you if you miss your one punch chance