Judo

Judo, (Japanese, way of softness or gentle way), a martial art derived from ju-jutsu and a form of highly sophisticated wrestling.A contest takes place on a mat 9 m (30 ft) square. Outside the mat there is a safety area of 1 m (3 ft 3 in) all round. The tatami (mats) are made of compressed straw with a canvas covering and measure 2 by 1 m (6 ft 6 in by 3 ft 3 in). The mats are pushed together and held in place by a wooden frame. Modern-day mats are composed of vinyl-covered foam. A contest is judged by a referee within the contest area, plus two judges situated at opposite corners of the mat. The contest must take place within the limits of the area.
All judoka (competitors) wear the judogi (judo suit), a loose-fitting garment of white or off-white. The jacket is fastened by a belt which goes twice round the body and is tied with a square knot. The colour of the belt indicates the competitor’s standard. At the start the fighters face each other at a distance of 4 m (13 ft) and make a standing bow. This is a traditional courtesy and formality before and after a bout. The referee then calls hajime (begin). A bout lasts a minimum of 3 minutes and a maximum of 20. There are no rounds, as in boxing, but a decisive score may end the contest. If a contest is not a clear victory one way or the other, the judges indicate the winner with their batons and the referee has the deciding vote.
Fighters are judged on throwing technique (nage-waza), and holding technique (katame-waza). Violations and fouls are also determining factors. The main object is to score an ippon (full point), worth ten points. This may be awarded for a throw of considerable force; lifting the opponent from the mat to shoulder height; making an effective stranglehold or lock; maintaining a hold for 30 seconds. A fighter who just fails to make an ippon may be awarded a wazari (almost a point), worth seven points. Two wazari equal one ippon. Should a fighter score only one wazari but have a serious foul committed against him or her, then he or she can win outright. A fighter may also gain a yuko (five points) and a koka (three points).
Some of the main infringements and fouls are as follows: (1) sweeping an opponent’s leg from underneath him or her from the inside (it is allowed to hook the instep); (2) trying to throw an opponent by twining a leg round his or hers; (3) falling back deliberately when the opponent is clinging to one’s back; (4) the adoption of an exceptionally defensive attitude; (5) pulling an opponent down in order to start groundwork; (6) taking hold of an opponent’s foot or leg to start groundwork (unless unusual skill be shown in so doing); (7) putting a hand, foot arm or leg directly on an opponent’s face or seizing his or her judogi in the mouth; (8) applying joint locks except at the elbow joint.