As a sport evolves, the level of athlete and skill gets better and better. In jiu-jitsu and judo, a black belt is reached in the gym after years of practice and showing a mastery of the techniques.
However, there is a big difference between a black belt and world class black belt competitor. In this video from an AJIFF tournament, a judo world champion squares off against ten different judo black belts.
The event was the 50th Anniversary of Tenri Judo Dojo in Los Angeles
Judo is a martial art that was born in Japan, and it is now known around the world as an Olympic sport. Judo was established in 1882 by combining jujitsu, a form of wrestling, with mental discipline. The roots of jujitsu lie in sumo, which has a long, long history; sumo is mentioned in the Nihon shoki (Chronicle of Japan), a document from 720 that describes the history of Japan from the mythical age of the gods until the time of Empress Jito, who reigned from 686 to 697.
From the twelfth to the nineteenth century Japan was ruled by the samurai, a class of professional soldiers. This provided fertile ground for various martial arts to develop. In addition to fighting with swords and bows and arrows, the samurai developed jujitsu to fight enemies at close quarters on the battlefield. Several different styles of jujitsu evolved, and hand-to-hand combat spread as an important form of military training.