Brazilian Jujitsu
Credit: Daniel Vorley / Getty Images

It was called the "Gracie Challenge." Starting in the Twenties, Carlos and Helio Gracie, the undersize founders of Brazilian Jujitsu, tested their budding fighting system by extending an open invitation to fighters of any style to come to Rio and engage them in actual combat. In dozens of fights, the Gracies rarely lost, and the string of successes resumed decades later with the arrival of their descendants in America. In the steel-cage Ultimate Fighting Championship, the Gracies went up against the guys everyone thought would win (powerful strikers and kickers), took them to the ground, wrestled them into position, and applied strangles and joint locks that forced them to give in or face broken limbs or loss of consciousness. "Now, all serious martial artists have knowledge of jujitsu," says Helio's son, Rickson Gracie, who runs the Rickson Gracie Jiu-Jitsu Center in Los Angeles and is undefeated in more than 400 bouts. "Without grappling, they'd feel naked out there."

Some argue that in a fight against multiple assailants, grappling can leave the attackers free to stomp your head into the pavement. But others point out that against two or more guys, you're pretty much screwed anyway, so you might as well benefit from the superior one-on-one skills of Brazilian jujitsu. "Taking a bigger guy to the ground is like taking a non-swimmer into the pool," says Steve Kardian, a cop and jujitsu trainer who spent 15 years studying karate before switching to BJJ. Jujitsu academies novices are quickly indoctrinated into these anaconda-like skills, practicing their moves by rolling around with a partner, exerting their full force to get him to submit – in a word, fighting. "When I first took the Rickson Gracie seminar, I was a karate black belt," says Kardian. "But guys with just one year of BJJ were able to close the distance, take me down, and finish me." He doesn't say what the second-year students did to him.

When to use it: A pervert is attacking a woman!

How to use it: The attacker sees you coming and throws a right, but you – the gallant Brazilian Jujitsu student – duck the punch, close the distance, and lock your arms around the back of the attacker's thighs. You lift up, push forward, and throw the creep to the ground. Instinct tells the perp to turn over. When he does, you apply the Mata Leao ("Lion Killer"), your biceps and forearm cutting off blood flow in the carotid arteries, resulting in unconsciousness in seconds.