Royce Gracie was the UFC 1 tournament champion and went on to also win UFCs 2 and 4, compiling an overall MMA record of 15-2-3. Going in to UFC 1, Royce was on a mission to prove that the fighting style his family refined throughout the years could defeat all the other well-known styles. Royce dominated the early UFCs, submitting nearly every opponent. He finished all but one of his first eleven fights by submission, finishing the other one via TKO from a dominant position. From the early to late 90's, it was almost universally agreed upon that jiu-jitsu was the most effective martial art in a real fight. On May 1, 2000, Royce suffered his first professional defeat at the hands of Kazushi Sakuraba via TKO. Sakuraba became known as the "Gracie Hunter," as he also had wins over Royler, Renzo, and Ryan Gracie. It was around this time that MMA was gaining more popularity and more participants, so fighters were beginning to adapt their styles and become well-rounded. Royce Gracie showed that if a jiu-jitsu expert went into the cage or ring against someone without any grappling experience, the odds were in the jiu-jitsu practitioner's favor.
As the UFC began to gain more notoriety, more stars with different backgrounds began to develop. In the late 90's and early 2000's, former Division I wrestler Chuck Liddell began to take the sport by storm. Liddell was a power puncher, who used his wrestling to counter his opponents' takedowns and keep the fight on the feet. Using this strategy, Liddell scored 13 knockout victories and eventually became the UFC Light Heavyweight champion. His style was nearly the complete opposite of Royce Gracie's. So where does jiu-jitsu come into play? Liddell started his jiu-jitsu training in the late 90's during the start of his MMA career. He was submitted in his third professional fight by submission specialist Jeremy Horn. However, since that fight, Liddell competed in 27 more professional fights and never again suffered defeat via submission. He even went on to avenge his loss against Jeremy Horn in 2005, this time winning by TKO. While Royce's jiu-jitsu was used offensively to finish fights, Chuck Liddell used his jiu-jitsu in a purely defensive manner, keeping his matches on the feet and utilizing his striking to put his opponents away.
The first women's fight in UFC history took place on February 23, 2013. Since then, the women's divisions have been some of the most exciting and competitive in the sport. Brazilian Jiu-Jitsu black belt Amanda Nunes currently holds the UFC bantamweight and featherweight titles. Her run in the promotion has been nearly flawless, compiling a 15-1 record with 10 finishes. Amanda's style represents a very modern approach to the game. Though she is most well known for her striking, she started her jiu-jitsu training at age 16 and has trained the martial art consistently throughout her professional career. Amanda's style represents the current apex of the sport as she has highly developed skills in every area of a fight. She currently holds 4 wins by submission and has proven that she has finishing skills on the feet and on the floor.
The UFC currently has 11 champions across all of its male and female divisions. Out of these 11 champions, 6 currently hold the rank of black belt in Brazilian Jiu-Jitsu. Ultimately, jiu-jitsu is an absolutely necessary part of a high level fighters' training program. Whether they plan to finish the fight on the ground with a submission or simply gain enough awareness to defend against common submission threats, it's clear that jiu-jitsu is highly effective and is only going to further evolve over time.