I thought I'd go way way back today and talk a little bit about the history of the sport.
From the beginning of my interest in MMA in the mid-1990's, I always thought it was ironic that two of the biggest schools of fighting -- as represented by the superstars of the day Royce Gracie and Ken Shamrock -- were total hybrids. Royce practiced Brazilian Jiu Jitsu -- the Latin American descendent of the ancient Japanese martial art of the samurai.
Ken's lineage was also interesting -- Japanese Catch Wrestling. He came out of a period of Japanese pro-wrestling when the sport aspects became increasingly dominant over spectacle, culminating in the launch of Pancrase a (nearly) all legit league with a heavy emphasis on submissions, especially leg locks.
At the time I thought that the Japanese had just gotten so fascinated with American pro-wrestling in the 1980's and 1990's that they traced it to its roots in 19th and early 20th century carnival attractions, but it turned out I was wrong.
It goes way further back than that. Check this:
Ad Santel, born Adolph Ernst, was a practitioner of catch wrestling.
Ad Santel fought one of the early clash-of-the-styles matches in modern martial arts history against Tokugoro Ito, a 5th degree black belt in Judo from Japan, who claimed to be the world Judo champion. Santel defeated Ito and proclaimed himself the world Judo champion.
Ad Santel fought Judokas from the Kodokan from 1914-1921. The judokas he fought included 4th degree black belt Daisuke Sakai and 5th degree black belt Reijiro Nagata, all of whom Santel defeated. Ad Santel also drew with 5th degree black belt Hikoo Shoji. The challenge matches stopped after Santel, yet to be defeated at the hands of any Kodokan representative, gave up on the claim of being the world Judo champion in 1921 in order to pursue a career in full time professional wrestling.
The impact of these performances on Japan was immense. The Japanese were fascinated by the submissions taught in catch wrestling. Japanese fighters travelled to Europe in order to either participate in various tournaments or to learn catch wrestling at European schools such as Billy Riley's Snake Pit in Wigan, UK.
And from the great OntheMat, here's more on how Santel's tradition was passed on to a generation of Japanese fighters:
Legendary catch wrestler and a student of Billy Riley's Snake Pit in Wigan, England, Karl Gotch taught catch wrestling to Japanese professional wrestlers in 1970's. His students were the likes of Antonio Inoki, Tatsumi Fujinami, Hiro Matsuda, Osamu Kido, Satoru Sayama (the legendary Tiger Mask) and Yoshiaki Fujiwara.
Starting from 1976, one of these professional wrestlers Antonio Inoki, would go on to host a series of mixed martial arts bouts against the champions of other disciplines. This resulted in unprecedented popularity of the clash-of-the-style bouts in Japan. His matches showcased catch wrestling moves like the Sleeper hold, Cross arm breaker, Seated armbar, Indian deathlock and Keylock.
Karl Gotch's students formed the original Universal Wrestling Federation (Japan) in 1984 which gave rise to shoot-style matches.The UWF movement was led by catch wrestlers and gave rise to the mixed martial arts boom in Japan. Catch wrestling forms the base of Japan's martial art of shoot wrestling. Japanese professional wrestling and a majority of the Japanese fighters from Pancrase, Shooto and the now defunct RINGS bear links to catch wrestling.
Notable mixed martial artists with traceable catch-wrestling links are numerous; among them are Kazushi Sakuraba, who trained in the UWF Snake Pit--a gym founded by catch wrestler Billy Robinson--as well as Masa Funaki and Ken Shamrock, both of whom trained under Karl Gotch and Yoshiaki Fujiwara. Some other important mixed martial artists with ties to catch include Josh Barnett, Frank Shamrock, Kiyoshi Tamura and Erik Paulson.
Along with the jiu jitsu by way of Brazil, catch wrestling by way of Japan is clearly a dominant thread in the sport. I'd say the other major threads are: olympic wrestling, muy thai, kickboxing (with a big Dutch tradition), and boxing. Other disciplines are beginning to have an impact -- particularly Tai Kwan Do (Stephan Bonnar, David Loiseau), Judo (Karo Parisyan, Kazuhiro Nakamura) -- but I'd say they have yet to become central.