I was told this by a thirty year kung fu practitioner....a bjj student came into his class wanting a "challenge" match with one of his black belts. the instructor said 'sure' and headed out to the parking lot. the bjj guy was confused thinking they were going to stay in the studio to fight. when he finally got wind of what was going on he backed out of the challenge-- the bjj guy decided to "show" them some moves instead. after 15 minutes of "showing" the kung fu guy asked him to go out to the parking lot and do those same moves--even offered $100 to do it. the bjj guy didn't. I wasn't there personally but I know of another bjj guy backing out of a challenge match when his opponent was going to use all of his weapons(mt guy)--the bjj guy didn't want him to use his elbows. so, I'm sold on the effectiveness of bjj in the ring on a cushy mat but royce would have lost to severn on the street.............cement plays more of a role than people want to admitt and every grappler i know says to stay off the ground in a fight. so i would not discount a good kung fu guy in the street.