I've rolled with 2 Blacks. One of the blacks was an older japanese woman and she wasn't even BJJ blue belt caliber technique wise and she was small, besides being relentless in her attack, there was no threat. The other black belt is a long time friend of mine and he's a blue belt in BJJ but mostly because he's ridiculously strong. I'm not going to say their names for their sake. Both of them can toss me around with their eyes closed (maybe not the lady) but once it's on the ground, it's my turn. Believe me or not, doesn't matter to me.