UFC 57: Liddell vs. Couture 3 was a mixed martial arts event held by the Ultimate Fighting Championship on February 4, 2006. It was held at the Mandalay Bay Events Center on the Las Vegas Strip in Nevada, and broadcast live on pay-per-view in the United States.

Headlining the card was an anticipated rubber match between top UFC stars and former coaches of The Ultimate Fighter Chuck Liddell and Randy Couture, widely touted and marketed as MMA's first major trilogy.

It was the UFC's largest grossing gate to date, $3.3 million , in addition to an estimate of over 400,000 pay-per-view buys. The disclosed fighter payroll for the event was $667,000.

Randy Duane Couture (pronounced /koʊˈtʊər/; born June 22, 1963) is an actor, retired American mixed martial artist, collegiate and Greco-Roman wrestler. During his tenures in the Ultimate Fighting Championship (UFC), Couture became a three-time UFC Heavyweight Champion, two-time UFC Light Heavyweight Champion, an Interim UFC Light Heavyweight Champion, and was the UFC 13 Heavyweight Tournament Winner. Couture is the first fighter to hold two UFC championship titles in two different divisions (heavyweight and light heavyweight). Couture has competed in a record 15 title fights. He holds the most title reigns in the UFC with five. His last fight with Lyoto Machida marked his 24th fight in the UFC, the third most amount of fights in the UFC (Tito Ortiz is first with 26 and Matt Hughes is second with 25). Couture is one of the first members of the UFC Hall of Fame. He is the only person over the age of 40 to have won a UFC championship fight, having done so four times.^{[citation needed]}

Couture was an Olympic wrestling alternate and has lived in Corvallis, Oregon, throughout much of his career, where he served as an assistant wrestling coach and a strength and conditioning coach for Oregon State University. He established Team Quest with Matt Lindland and Dan Henderson, a training camp for fighters, based out of Gresham, Oregon, and headed by coach Robert Folis. In 2005, Couture moved to Las Vegas, where he opened his own extensive chain of gyms under the name Xtreme Couture. He currently trains at his Las Vegas-based gym. Couture partnered with Bas Rutten in the opening of Legends Gym in Hollywood, California.

Charles David "Chuck" Liddell (born December 17, 1969) is a retired American mixed martial artist and former Ultimate Fighting Championship light heavyweight champion. Liddell has an extensive striking background in Kempo, Koei-Kan karate and kickboxing, as well as a grappling background in collegiate wrestling. Liddell is known for his Knockout power, Iron chin, Excellent counter striking and for his sprawl-and-brawl technique, which made him one of the most difficult fighters to takedown. He is one of the most dominant champions that ever competed in the UFC. He still holds the record for the most knockouts in UFC history. As of his retirement, Liddell has had 23 fights in the UFC. Along with fellow UFC Hall of Fame fighter Randy Couture, Liddell is widely credited for bringing mixed martial arts into the mainstream of American sports and entertainment. On July 10, 2009, he was inducted into the UFC Hall of Fame.

Liddell began studying Koei-Kan karate at the age of 12; the tattoo seen on his scalp reads "Koei-Kan". Liddell was a four-year starter on the football team at San Marcos High School. While growing up in Santa Barbara, he often frequented the infamous Del Playa Drive, the middle of the party scene of the college town of Isla Vista, where he often found himself in fights with drunk college students. He became a Division I wrestler at California Polytechnic State University, San Luis Obispo and graduated with a Bachelor of Arts Degree in Business/Accounting in 1995. He holds an amateur kickboxing record of 20 wins and 2 losses, with 16 of his wins coming by way of knockout.

Renato da Cunha Sobral (Portuguese pronunciation: [ʁeˈnatu soˈbɾaw]; born September 7, 1975), also known as "Babalu", is a Brazilian mixed martial artist, and former Strikeforce Light Heavyweight Champion. He is noted for holding on to chokes for too long. Sobral previously fought in the Ultimate Fighting Championship, where he posted a 6–4 record. He is a member of the Gracie Barra Cerritos and has a Brazilian Jiu-Jitsu black belt under Carlos Gracie Jr. Some of his MMA achievements include defeating fighters Trevor Prangley, Maurício Rua, and Jeremy Horn in a single night at IFC's Global Domination tournament. Sobral also holds wins over Chael Sonnen, Robbie Lawler, and Cyrille Diabaté.

Sobral's background is in wrestling. Before joining the Gracie Barra Combat Team he was a Brazilian national wrestling champion and was trained in Ruas Vale Tudo, a martial arts system developed by Marco Ruas.

At UFC 62, Sobral was defeated by Chuck Liddell in a bout for the UFC Light Heavyweight Championship. The match was stopped as a technical knockout at 95 seconds into the first round. Following his loss to Liddell, Sobral faced Jason Lambert at UFC 68. Sobral was knocked out in the second round.

Diego J. Sanchez (born December 31, 1981) is an American mixed martial artist (MMA) of Mexican descent, with a background in wrestling and Gaidojutsu, system of submission wrestling developed by his longtime trainer Greg Jackson. He currently fights as a welterweight with the Ultimate Fighting Championship (UFC). Sanchez is currently ranked as the #9 welterweight fighter in the world by MMAWeekly.

Sanchez was born in Albuquerque, New Mexico. He attended Del Norte High School, where he became a state champion wrestler.^{[citation needed]}

Diego Sanchez wrestled in New Mexico before starting training MMA while working for UPS. Sanchez eventually joined Jackson's Submission Fighting, still while working for UPS, managing the time between work and training. In 2002, he made his MMA debut for King of the Cage where he also later became a champion.

His UFC debut came when he was chosen as a participant on the first season of the reality show, The Ultimate Fighter. Presented as a young, focused middleweight who only had one goal, to become a UFC champion, he won a contract with the UFC after winning a fight against Kenny Florian, becoming the middleweight winner for the first season of the show. On the show, Sanchez was known for being the "odd-ball" of the group, practicing yoga at odd moments and trying to extract "energy" from a lightning storm, and was also a self-proclaimed "Zen master". Sanchez' last fight before his loss to Josh Koscheck was against Joe Riggs on December 13, 2006 at UFC Fight Night 7. Sanchez landed a right hook that knocked Riggs down, followed by a running knee that knocked Riggs out. Sanchez won at 1:45 of the first round, scoring the first UFC knockout of his career.