I knew a guy who trained in ninjitsu in highschool. I trained in Kung Fu for a few years before I met him. We used to spar after school and he was ridiculously hard to fight. All of his moves were deceptive. Even simple kicks and blocks were meant to decieve. As a result I was constantly trying to predict his actual motive instead of just fighting him straight-up. It's a really neat style that seems to be very effective against other trained martial artists. Idk how it would fare against an untrained street fighter, but I'd guess that it is just as effective in that situation too.