Tested on the battlefields of feudal Japan, Jiu Jitsu was the hand-to-hand combat art of the Samurai. Judo and Brazilian Jiu Jitsu both evolved out of this ancient fighting style – but where Judo focused on the standing aspect – Brazilian Jiu Jitsu focues on the ground/grappling aspect, as the theory that 90% of fights ends up on the ground. If this fact is true – and all signs point that it is close – BJJ may be the most effective martial art ever devised.