Judo

Judo was originally known as Kano Jiu-Jitsu or Kano Jiu-Do, and later as Kodokan Jiu-Do or simply Jiu-Do or Judo. In the early days, it was also still referred to generically simply as Jiu-Jitsu. Japanese polymath and educator Jigoro Kano is regarded as the founder of judo. Kano was a small, frail boy, who, even in his twenties, did not weigh more than a hundred pounds and was often picked on by bullies. He first started pursuing jujutsu, at that time a dying art, at the age of 17, but met with little success. When he went to university to study literature at the age of 18, he continued his martial arts studies which is said to have emphasized technique over formal exercise, sowing the seeds of Kano's emphasis on free practice in judo.

Kano was devising new techniques, such as the "shoulder wheel" (kata-guruma, known as a fireman's carry to Western wrestlers who use a slightly different form of this technique) and the "floating hip" (uki goshi) throw. However, he was already thinking about doing far more than just expanding the canons of Kitō-ryū and Tenjin Shin'yō-ryū. Full of new ideas, Kano had in mind a major reformation of jujutsu, with techniques based on sound scientific principles, and with focus on development of the body, mind and character of young men in addition to development of martial prowess.

While judo includes a variety of rolls, falls, throws, hold downs, chokes, joint-locks, and strikes, the primary focus is on throwing, and groundwork. Throws are divided in two groups of techniques, standing techniques, and sacrifice techniques. Standing techniques are further divided into hand techniques, hip techniques, and foot and leg techniques. Sacrifice techniques are divided into those in which the thrower falls directly backwards, and those in which he falls onto his side.

The ground fighting techniques are divided into attacks against the joints or joint locks, strangleholds or chokeholds, and holding or pinning techniques.

A kind of sparring is practiced in judo, known as randori, meaning "free practice". In randori, two adversaries may attack each other with any judo throw or grappling technique. Striking techniques such as kicking and punching, along with knife and sword techniques are retained in the kata. This form of pedagogy is usually reserved for higher ranking practitioners, but are forbidden in contest, and usually prohibited in randori for reasons of safety. Also for reasons of safety, chokeholds, joint locking, and the sacrifice techniques are subject to age or rank restrictions. For example, in the United States one must be 13 or older to use chokeholds, and 16 or older to use armlocks.

In randori and tournament practice, when an opponent successfully executes a chokehold or joint lock, one submits, or "taps out", by tapping the mat or one's opponent at least twice in a manner that clearly indicates the submission. When this occurs the match is over, the tapping player has lost, and the chokehold or joint lock ceases.