BJJ was largely unknown outside of Brazil (and, to a limited extent, Japan) until the introduction of the Ultimate Fighting Championship, a mixed martial arts competition in which combatants fought full contact and were allowed to use any technique whatsoever.
All of a sudden, everyone wanted to learn "Gracie jujitsu". The reason? Time after time, Royce Gracie emerged victorious at the UFC. Karate men, ninjutsu masters, savate professeurs and boxers were all forced to tap out as Royce took them to the ground and systematically worked his way into a position where he could choke or joint-lock his opponents into submission. In almost every case, Royce was considerably smaller than his opponent. It was incredibly inspiring and envy-inducing.
The Gracies, entrepreneurs that they were, wasted no time trumpeting their art's "street effectiveness." The previous commonsense mentality was that going to the ground in a street fight was the worst thing you could do, but every time, the Gracies would point to Royce's victories in the U.S. (and his brother Rickson's far more impressive victories in Japan.) The Gracies would further claim that their's was the most important and practical system to learn, because based on their experience fighting on the streets of Rio de Janeiro as well as in numerous challenge matches, "ninety percent of all fights go to the ground."
Many other stylists had valid objections to the Gracie philosophy. But it's hard to argue with such a dominating win record, which the Gracies surely had. So, for at least a couple years, most people bought into the Gracies' arguments that groundfighting expertise, particularly of the BJJ variety, would be enough to carry the day almost all the time.
Then, the Gracie record started evening out. Gracie fighters started losing - at first, only to other Brazilian jujitsu opponents (mostly from Brazil), then to proponents of other grappling styles such as wrestlers and judo players, and then finally, to strikers as well. To be sure, the practitioners of Gracie jujitsu were still (and probably always will be) a force to be reckoned with when competing in a controlled environment, but their aura of invincibility was gone. This was key to opening the way to an honest examination of the effectiveness of BJJ in a real-life situation.
