Vitali Klitschko (Ukrainian: Віта́лій Володи́мирович Кличко́ [transliteration: Vitali Volodymyrovych Klychko], [ʋiˈtɑʎiɪ̯ klɪtʃˈkɔ]; English: /vɨˈtæli ˈklɪtʃkoʊ/; born 19 July 1971) is a Ukrainian professional boxer and the reigning WBC Heavyweight Champion. He is a leader of the political party UDAR of Vitaliy Klychko and a member of the Ukrainian delegation to the Congress of the Council of Europe. He previously held the WBO and WBC titles. Klitschko is the first professional boxing world champion to hold a Ph.D. degree.

Klitschko is known for his powerful punches and durable chin. With a 86.96% knockout percentage rate, he holds the second best knockout-to-fight ratio of any champion in heavyweight boxing history, after Rocky Marciano's 87.76%. He has never been knocked down in any professional boxing bout and has also never lost a decision. His two losses have come via a shoulder injury during a fight and a deep cut above his eye, which were recorded as TKO losses. His power and his possession of a Ph.D have led to his nickname, Dr. Ironfist.

Cristobal Arreola (born March 5, 1981) is a Mexican American professional Heavyweight boxer. Arreola is the former NABF, WBC Continental Americas, and current WBC FECOMBOX Heavyweight Champion. Chris is promoted by Goossen Tutor and trained by Henry Ramírez.

Arreola was born in Los Angeles, California. Chris met Legendary Boxing Champion Julio César Chávez a couple of times when he was a kid. Chris said "I had a chance to go to his house in Culiacán, Mexico because my father was from near there and my aunt lived in Culiacan. I used to go and watch him train."

Arreola grew up in East LA; his father was a boxer and started him boxing at the age of eight with trainer Hector Rodríguez. At 16, he had "about 200 amateur bouts" before losing interest and quitting. In 2001 at 20 he got back into boxing and after only three months of training managed to win the National Golden Gloves at the Light Heavyweight division, to win Chris beat Dallas Vargas who had about 300 amateur fights at the time.

After another hiatus from boxing, this time for two years, he tried to come back for the 2003 Golden Gloves but arrived shortly after the check-in deadline prompting him to turn pro.

Cornelius "Corrie" Johannes Sanders (born on 7 January 1966 in Pretoria, South Africa) is a South African former professional boxer. In 2003 he became the WBO heavyweight champion by defeating Wladimir Klitschko via a second-round knock out that is considered one of the biggest upsets in heavyweight boxing history and won Ring Magazine upset of the year 2003.

Sanders began his boxing career with a first round knockout of King Kong Dyubele on 2 April 1989.

He won his first 23 bouts, 15 by knockout. Among the fighters he defeated during that streak were Steve Zouski, Art Card, future WBO cruiserweight champion Johnny Nelson and future world title challenger Bert Cooper.

In his 24th bout, on 21 May 1994, he suffered his first defeat, at the hands of Nate Tubbs via a second round knockout.

He fought 12 more times over the next five years, including a first round knockout over former world cruiserweight champion Carlos De León and a second round knockout over another former world champion, Bobby Czyz. A stoppage loss to future heavyweight champion Hasim Rahman in a bout Sanders was winning confirmed his ability and also his vulnerability. Returning to the ring in 2001 he scored a quick win over Michael Sprott and then followed this up with a defeat of Otis Tisdale in 2002. Corrie Sanders' biggest weapons are his southpaw fast hands which he uses to knock fighters out early.

Orlin Levance Norris, born October 4, 1965 in Lubbock, TX, is an American boxer who held the WBA cruiserweight title and fought in several noteworthy boxing matches in the 1980s and 1990s. He is the lesser known brother of retired former champion Terry Norris.

As an amateur, he won the National Golden Gloves title.

Norris turned pro in 1986 as a heavyweight and became a highly ranked and much avoided contender. Although only 5'11, and not a big puncher, Norris relied on his fine boxing skills to outbox and pile up points versus his much larger opponents.

In 1988 he won the NABF heavyweight title with a decision over the towering Larry Alexander, and followed it up with more easy points wins over respected challengers Renaldo Snipes, Jesse Ferguson, and ex-world champion Greg Page (boxer).

Page had been considered as an opponent for Evander Holyfield, however after defeating Page, the shot was not offered to Norris. In 1990 he was outboxed by crafty ex-world champion Tony Tubbs (a decision later changed to a no-decision after Tubbs tested positive for an illegal substance), and followed up that momentum killer with a further loss, an 8th round TKO to hard hitting Bert Cooper, where Norris was decked in the 8th round and twisted his knee, unable to continue.

Wladimir Klitschko (Ukrainian: Володи́мир Володи́мирович Кличко́ [transliteration: Volodymyr Volodymyrovych Klychko], born 25 March 1976) is a Ukrainian heavyweight professional boxer. Klitschko is the WBA (Super), IBF, WBO, IBO & The Ring Heavyweight Champion. His older brother Vitali Klitschko is the current WBC Heavyweight Champion. Klitschko is the longest reigning Heavyweight Champion in history for the IBF, WBO & IBO Heavyweight titles, both in measurements of defenses and time & overall the 6th longest reigning Heavyweight Champion of all time. As of 2011, Boxrec rates Klitschko as the number 2 pound-for-pound in the world. Ring Magazine currently rates Klitschko as the number six pound-for-pound boxer in the world.

Since 2005, Klitschko has been the dominant force in the heavyweight division, defeating a majority of the top heavyweights in the rankings. When Klitschko won the IBF title against Chris Byrd there were four separate Heavyweight Champions. Since then, he has unified the IBF, IBO, WBO & WBA belts and defeated the WBA Champion in recess. Following his win over Ruslan Chagaev, Klitschko was awarded the vacant Ring Magazine Heavyweight title.