Judo has a complex scoring system

The martial art had its origins in jujitsu, and it came as no surprise when Japanese judoka won gold in three of the four weight classes.

The hosts did not have it all their own way, however, as Dutchman Anton Geesink beat Japan's national champion Kaminaga Akio to win the open class.

There was a brief exile when judo was dropped for the Mexico City Games, but it was back for Munich in 1972.

Women did not compete for Olympic judo medals until 1992 but now enjoy equal status, contesting seven weight classes.

The open class, in which men of any weight could take part, was discontinued in 1984.

While Japanese judoka have traditionally dominated, the judo mat has also been a happy hunting ground for the French and the Koreans.

French heavyweight David Douillet became an Olympic legend when he won his second gold medal in Sydney four years ago.

His first medal was bronze in 1992, and four years later he avenged his Barcelona semi-final defeat to Naoya Ogawa by beating him on the way to winning gold in Atlanta.

Douillet recovered from a serious motorcycle accident to take gold again in Sydney with a controversial victory over Shinichi Shinohara.

Shinohara cried throughout the medal ceremony after having a decision which would have given Japan their fifth gold of the games overruled by the judges.

There was more controversy when Britain's Debbie Allan was not allowed to compete after she was adjudged to be too heavy for her weight category by 50 grams.