The Kodokan curriculum is not purely focused on sport competition, but modern practitioners frequently ignore non-sport elements.
The Kodokan Judo curriculum includes basics, techniques, and kata. These are internationally standardized, and rank is determined based on evaluation of these skills. Everyone studies basics and techniques. Competitors frequently ignore kata, while those who believe in judo as a martial art often study some kata.
- walking movements
- turning movements
- throws (nage)
- pins (osaekomi)
- chokes (shime)
- joint-locks (kansetsu)
Throws are also studied with counters (gaeshi) and combinations (renraku).
Judoka spend an inordinate amount of time distinguishing between techniques.
- Nage no Kata (throwing)
- Katame no Kata (ground grappling)
- Kime no Kata (traditional self-defense)
- Goshin Jutsu (modern self-defense)
- Ju no Kata (gentleness/flexibility)
- Itsutsu no Kata (principles of the flow of forces, from traditional Tenjin Shinyō-ryū jujutsu, preserving one root of Kano's system)
- Koshiki no Kata (also known as Kito-ryu no Kata, just a set of core techniques, preserving the other strand of origin of Kano's system)
As originally designed by the founder, techniques which are too dangerous to practice in randori are preserved and practiced in kata. These techniques include striking, responses to striking, joint locks against joints other than the elbow, and defending weapons including knives, swords, and pistols.
My personal view is that judo kata is a poor preparation for striking. Many attacks are cariactures; practicing them does not make you a better striker, and opponents should not be expected to be so generous in telegraphing their attacks.
Proficiency in kata is nominally required to advance in rank, though in practice I think this rarely happens. A great premium is placed on competition record for promotion.
Safety and Combat Training
Judo's contribution to martial arts according to the founder was it's emphasis on randori training, where practitioners train in a non-cooperative but relatively safe manner. The set of permitted techniques is intentionally restricted to balance safety with the liveness of full-force techniques. This contrasts with kata, where safety is achieved through prearranged sequences, which was dominant at the time of judo's founding.
No obviously superior method has been developed to improve judo randori's mix of safety and liveness. Other systems (BJJ) believe the set of relatively safe techniques is slightly different, but no method of training unrestricted full force striking on partners exists where the injury rates are acceptable. Attempting to train "street" or "real world" combat necessarily generates more injury risk. Application to combat obviously requires extrapolation, but judo's conclusion to this problem is that it is better to actually train full-force with a restricted set of techniques than it is to simulate using all techniques. Judo displaced its contemporary jujutsu because the randori training method was superior to the alternative
I have never seen a judo school focus on street combat ("real world" combat). There is a division between practitioners who believe judo is purely a sport versus a martial art, but this is at the individual level. Randori is a foundational judo training element due to the injury concerns, even if your intention is to train judo for combat rather than sport.
The way techniques are practiced in their formal setting often differs substantially from the way they are performed in competition. In Nage no Kata, for example, throws finish with the thrower in a superior position: standing, balanced, and with control of the partner's arm to guide their fall and control their movements afterward. To succeed in competition, as long as a throw is scored as an ippon, the match ends. You will often see the thrower roll through and end up in an inferior position, but because the throw is scored an ippon, this inferior position does not matter in the sport setting. This difference is important for self-defense considerations but is not related to the curriculum.
Types of Judo Competition
The dominant form of judo competition is governed by the International Judo Federation (IJF). This shiai competition is the international sport you see at the world championships and Olympics. The rules for IJF judo change every few years.
Other types of judo competition exist:
- Kata - Pairs perform for judges and are scored.
- Kosen - this alternate rule set results in substantially more groundwork and is practiced at some Japanese universities
- Freestyle - Another alternate rule set with different scoring, similar to previous versions of IJF rules where grips on legs were allowed.
- groundwork only - appears in local competitions