I can remember in the 80's traditional martial arts like Kung Fu and Karate were the hot thing. Bruce Lee made Kung Fu popular throughout the 70's, as did the show (called 'Kung Fu). Hollywood popularized Karate through popular names like Chuck Norris and through movies like the Karate kid.
Back then the conventional wisdom told us that if someone is a black belt in Karate for Kung Fu - "Don't mess with that guy!"
In came mixed martial arts and the iconic Gracie family. Has anyone seen UFC 1? Although most of those fighters would get slaughtered today, it is arguably the most entertaining UFC bouts ever made. It pitted single-art fighters against each other. A kick boxer verse a Sumo wrestler, a traditional boxer vs BJJ, etc. No weight class and almost no rules.
In the early stages of UFC the Gracies dominated, particularly Royce Gracie. Time and time again their Brazilian Jiu Jitsu would crush traditional martial artists and it soon became clear arts like Karate and Kung fu are relatively weak.
In a short time the very face of martial arts was changed in the US (and world I presume). The UFC also went through relatively quick changes. Fighters began adopting more practical arts, most commonly Brazilian Jiu Jitsu for ground work and various versions of Kick Boxing (as well as straight boxing) for striking. The sport also became very controversial, and as a result some limiting rules were put in place. The UFC also tinkered with different fighting formats.
Martial arts outside the UFC went through big changes as well. . Today our cities and towns are flooded with studios who generally teach (with some variation) Brazilian Jiu Jitsu combined with Muay Thai (a variation of kick boxing). Even the US Marine Corps and US Army have used BJJ to subliment their hand-to-hand combat training. The US Army simply calls it, US Army Combatives.
Let's rewind a little bit. It is said, although I cannot confirm, that the Gracie family invented Brazilian Jiu Jitsu - which is why some refer to it as "Gracie Jiu Jitsu." The Gracies are a large family with lots of male siblings. As the story goes a Japanese Judo master befriended and tought one, who in turn made some changes (creating Brazilian Jiu Jitsu) and he tought the others. Judo is an old Japanese art that focuses on throws, trips and sweeps, with some follow on ground work. The Gracies focused entirely on the ground work of Judo, refining, improving it, and thus creating the a new art.
I have always been a huge Brazilian Jiu Jitsu fan, but I recently started becoming a big fan of traditional Judo. A few MMA fighters have been able to utilize Judo with some success, but they do have a disadvantage. They're not fighting on hard flooring or concrete as you would be on the street. The surface of fighting rings are generally made to have some give in order to prevent injury. Also, you're going up against shirtless, sweaty guys so there's less to grab and they're slippery. That can certainly be the case on the street, but most of the time your opponent will be wearing some type of clothing you can grab and use. Even a T-shirt allows for some choke techniques.
So, I've began taking Judo classes. I'm able to hang decently against the experienced Judo guys on the ground (I have limited BJJ experience). But when it comes to stand up Judo, the take downs and such, I'm pretty weak against those guys. I've only gone to 4 classes so far and I have been seeing improvement each time. It's also fantastic cardio!