Clinch fighting (also referred to as clinch work) is the part of stand-up fighting where the combatants are grappling in a clinch, typically using clinch holds. Clinching the opponent can be used to eliminate the opponent's effective usage of some kicks, punches, and mêlée weapons. The clinch can also be used as a medium to switch from stand-up fighting to ground fighting by using takedowns, throws or sweeps. Clinch fighting is emphasized in Greco-Roman Wrestling, Freestyle Wrestling, Catch wrestling, Shoot wrestling, Judo, Mixed martial arts, San Shou, Muay Thai, Sambo and Sumo.

Clinch fighting is the primary focus of many combat sports such as Judo and it is also a fundamental part of Amateur Wrestling, Sambo, Muay Thai and Mixed martial arts. The nature of the clinch is fighting in each sport depends on the rules involved. Muay Thai puts much emphasis on strikes from the clinch, while Judo focuses on throws. The rule common to all these forms is the allowance for the grappling necessary to form a clinch. Others combat sports like Boxing or Taekwondo only allow clinching for a short time or do not allow it at all. If clinching is disallowed, the clinching fighter will be issued a warning, or the referee will restart the fight from a distance.

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.

Tim Tackett is a martial arts instructor and author from Redlands, California who runs a non-profit group dedicated to preserving Bruce Lee's art of Jeet Kune Do.

Tackett began training in the martial arts when he was stationed in Taiwan in 1962 while serving in the United States Air Force. On the recommendation of a friend, he began studying martial arts intensively. During his 3 years in Taiwan he learned two types of Hsing-i, T'ai chi, Northern and Southern Shaolin, White Crane, and Monkey style kung fu. After his discharge from the Air Force in 1966, he opened a Gung Fu school in Redlands, California while attending the University of California, Riverside.

Tackett saw Bruce Lee demonstrate Jeet Kune Do in 1967 at Ed Parker's tournament in Long Beach, California. Busy with college and supporting a family he closed his Gung Fu school and focused on his education. Soon after receiving his M.F.A. in 1970 he began a career as a high school drama teacher (he is now retired) from Montclair High School then Etiwanda High School. Along with his first student Bob Chapman, he visited Dan Inosanto's backyard Jeet Kune Do school on the recommendation of Dan Lee. At that time the class consisted of about 10 students including Bob Bremer, Dan Lee, Richard Bustillo, Pete Jacobs and Jerry Poteet.

Anderson da Silva (Portuguese pronunciation: [ˈɐ̃deʁsõ ˈsiwvɐ]; born April 14, 1975) is a Brazilian mixed martial artist. He is the current UFC Middleweight Champion and the promotion's longest reigning champion. With 14 consecutive wins and 9 title defenses, Silva holds the longest winning streak and title defense streak in UFC history.

Silva is ranked as the number one Middleweight in the world by multiple publications, and is the consensus No. 1 pound-for-pound fighter in the world according to ESPN, Sherdog, Yahoo! Sports, MMAFighting.com and other publications. UFC president Dana White has proclaimed Silva as "the greatest mixed martial artist ever."^{[undue weight? – discuss]} Silva is also the last Cage Rage Middleweight Champion and a former Shooto Middleweight Champion. Besides the UFC and Cage Rage, Silva has fought for a number of other MMA promotions including the Pride Fighting Championships, Shooto and Rumble on the Rock.

Although known primarily for his mastery of Muay Thai striking, Silva is also a Brazilian Jiu-Jitsu blackbelt, a rank he earned in 2006 from Antônio Rodrigo Nogueira who follows Gracie Lineage through Carlson Gracie, like Murilo Bustamante and the Brazilian Top Team. He began martial arts training at the age of 14, training Tae kwon do and earning a black belt by the age of 18. He is also a black belt in Judo and a yellow rope in Capoeira.

Robert Alexander McCullough IV (born May 26, 1977) is an American Muay Thai kickboxer and mixed martial artist. He was a five-time World Muay Thai Champion^{[citation needed]}, and is a former WEC Lightweight Champion. He currently trains in Huntington Beach, California at HB Ultimate Training Center. His training partners include Jean Carrillo, Muay Thai boxing coach; and Rob Natzel, strength and conditioning coach.

McCullough began his MMA career with a first-round technical knockout victory at the Palace Casino in Lemoore, California, in 2001. Between 2003 and 2007, "Razor Rob" went 10-1 with nine stoppage victories and only a split-decision loss to Harris Sarmiento, which he later avenged.

McCullough defeated Muay Thai fighter Kit Cope at WEC 25 to win the vacant WEC lightweight title. He defended the title once by defeating Richard Crunkilton by first-round TKO. On February 13, 2008, he lost his title to Jamie Varner when Varner defeated him by TKO due to strikes in the third round.

After losing his title, McCullough struggled over his next four fights in the now-defunct WEC. He defeated Kenneth Alexander by split decision but then lost to Donald Cerrone. He defeated Marcus Hicks by majority decision, but he fractured his right hand and received minor damage to his ankle and subsequently underwent surgery to repair his hand. McCullough was expected to return to the cage against Anthony Pettis on November 18, 2009, at WEC 44; but Pettis had to pull out of the bout with an undisclosed injury. McCullough instead faced WEC newcomer Karen Darabedyan. McCullough lost to Darabedyan via split decision.