how would bas rutten do in boxing?

He would need specialized training first, even with this supreme knowledge and experience in other 'genres' of fighting. Mainly, he would need to get used to the distance in boxing. Boxers need to be comfortable being much closer to their opponent than in mma. Also, the stance is different, you can slip punches differently. His opponent would be able to get away with defensive moves in boxing that wouldn't have worked at all in mma, so he wouldn't be used to seeing them or prepared to capitalize on them...

Bas is a legend. IMO, im not really sure but id back him in a boxing match....if he was in his prime of course. He was a total beast. I like Bas a lot...one bad m*therf*cker...great coach, too. But he would suck as a boxer, just like Kimbo is a side-show right now. Boxing requires a completely different and specialized skill set than MMA and everything else. Being a great UFC guy, street-fighter, etc. just doesn't necessarily translate well to boxing. The same goes for the reverse. (By the way, have you ever checked out some of Bas's "bar fight" and "street defense" videos on Youtube? Hilarious!)