Kosen Judo and Brazilian Jiujitsu

Below is an excerpt from a brief article that appeared at Eastern Europe BJJ, comparing and contrasting Kosen Judo and Brazilian Jiujitsu. The full article may be found here. Enjoy!

What is/was Kosen Judo?
Kosen judo  was a refinement of Kodokan Judo that was developed and flourished at the Kōtō senmon gakkō technical colleges in Japan in the first half of the twentieth century. Kosen judo’s competition rules allowed for greater emphasis of ne-waza ( ground techniques) than in mainstream judo and it is sometimes regarded as a distinct style of judo. Today, the term “Kosen judo” is frequently used to refer to the competition ruleset associated with it that allows for extended ne-waza.

Such competition rules are still used in the shichitei jūdō / nanatei jūdō competitions held annually between the seven former Imperial universities.

Differently to modern Judo rules leglocks were allowed (Leglocks started being prohibited by Kodokan rules in 1914 in shiai and randori as well. By 1925 all joint-locks except elbow locks were totally prohibited together with neck cranks. Kosen rules being the Kodokan rules derivative did not allow leglocks absolutely).
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How is Kosen Judo different or similar to Brazilian Jiu-Jitsu?
If you look at the Kosen Judo video below you can see many moves and flows that are different from modern Judo ground work (which is much more focused on pinning and more static).  These videos were made in the 1970’s by 6 older judokas , among them (in the tapes) was the famous Masahiko Kimura himself (who beat Helio Gracie). When you look at the techniques displayed in the video, it looks very similar to Gracie Jiu-Jitsu (which is more focused on the basics than modern sport BJJ). Kosen Judo players also pulled guard in competition. Kosen had a pinning rule. Strategy is different than BJJ. There was more more turtling than BJJ etc.
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In short, Kosen Judo and Brazilian (Gracie) Jiu-Jitsu are similar but are still very different. Most of the techniques are the same, the competition rules are different. Kosen Judo has faded due to the popularity of modern Kodokan Judo (more focused on throws), while BJJ is fastly growing and always evolving with new techniques and flows.