As the UFC continued to work with state athletic commissions, events were held in smaller U.S. markets, including Iowa, Mississippi, Louisiana, Wyoming and Alabama. SEG could not secure home video releases for UFC 23 through UFC 29 in a period known by some fans as the "dark days" of the UFC.

So you can strike and grapple with your opponent in a UFC match, but how do you actually win? You can win by submission, indicated when your opponent either physically taps out or verbally submits. A fighter might submit if he is unable to defend effectively against strikes or if he is caught in a painful hold such as an armbar or ankle lock.

The big UFC became a hit on pay-per-view and home video almost immediately due to its originality, realism, and wide press coverage, although not all of it favorable. The nature of the burgeoning sport quickly drew the attention of the authorities and UFC events were banned in a number of American states.

Nate Quarry makes a successful return to the Octagon as he knocks out Pete Sell in the third round of a brusing fight.

Although "There are no rules!" was the tagline in the early 1990s, this was not strictly true; the UFC operated with limited rules. There was no biting, no eye gouging, and techniques such as hair pulling, headbutting, groin strikes and fish hooking were frowned upon, but allowed. In fact, in a UFC 4 qualifying match, two competitors Jason Fairn and Guy Mezger agreed not to pull hair as they both wore pony tails tied back for the match.

K-1 is a combat sport that combines stand up techniques from Muay Thai, Karate, Taekwondo, Savate, San shou, Kickboxing, traditional Boxing, and other martial arts to determine the single best stand-up fighter in the world.

The concept for a tournament to discover the world's best fighting style was the brainchild of Art Davie, a southern California-based advertising executive. Davie met Rorion Gracie in 1991 while researching martial arts for a marketing client. Gracie operated a Brazilian Jiu-Jitsu school in Torrance, California and the Gracie family had a long history of vale-tudo matches—a precursor of mixed martial arts—in Brazil. Davie became Gracie's student.

K-1 is a combat sport that combines stand up techniques from Muay Thai, Karate, Taekwondo, Savate, San shou, Kickboxing, traditional Boxing, and other martial arts to determine the single best stand-up fighter in the world. The most dramatic and hardest-hitting knockouts ever delivered on the K-1 tournament circuit with punches, kicks and knee strikes. Enjoy!

Ah, the knockout, the exclamation point of mixed martial arts. Though it can come in many different varieties – KO, TKO, KTFO – it’s always entertaining. Here are some great ones from the UFC.