Boxing

Boxing, also called pugilism, is a combat sport in which two people engage in a contest using only their fists. There are two forms of boxing: amateur and professional. Amateur boxing is an Olympic and Commonwealth sport and is a common fixture in most of the major international games - it also has its own World Championships. Boxing is supervised by a referee over a series of between one to three minute intervals called rounds. The result is decided when an opponent is deemed incapable to continue match by a referee or if an opponent is disqualified for breaking a rule, resigning by throwing in a towel, or by judges' scorecards at the end of the bout.
The birth hour of boxing as a sport may be its acceptance by the ancient Greeks as an Olympic game as early as 688 BC. Modern boxing evolved in Europe, particularly Great Britain and Germany. In 2004, ESPN ranked boxing as the most difficult sport in the world.
There are some boxing styles:
Boxer/out-fighter
Boxer-puncher
Brawler/slugger
Swarmers/in-fighter
Counter puncher
Combinations of styles.
Punches:
Jab – A quick, straight punch thrown with the lead hand from the guard position.
Cross – A powerful, straight punch thrown with the rear hand.
Hook – A semi-circular punch thrown with the lead hand to the side of the opponent's head.
Uppercut – A vertical, rising punch thrown with the rear hand.

Wladimir Klitschko is a Ukrainian heavyweight professional boxer. Klitschko is the WBA (Super), IBF, WBO, IBO & Ring Magazine 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 7th 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. He works behind a strong left jab and possesses one of the strongest right crosses in boxing. Klitschko is a safety first fighter; however, he tends to methodically break down his opponents over a series of rounds. Emanuel Steward, Klitschko's trainer, has also pointed out that Klitschko's ability to hurt opponents late on in fights (Tony Thompson, Samuel Peter, etc.) is a sign of his power. He has gone on to say that he feels Klitschko is one of the hardest punchers in heavyweight history.

Muhammad Ali is an American former professional boxer philanthropist and social activist. Considered a cultural icon, Ali was both idolized and vilified.
Originally known as Cassius Clay, Ali changed his name after joining the Nation of Islam in 1964, subsequently converting to Sunni Islam in 1975, and more recently practicing Sufism. In 1967, three years after Ali had won the World Heavyweight Championship, he was publicly vilified for his refusal to be conscripted into the U.S. military, based on his religious beliefs and opposition to the Vietnam War.Nicknamed "The Greatest," during his prime Ali fought in what has been described as the most talent rich landscape in heavyweight history, and was involved in several historic boxing matches.Ali had brought beauty and grace to the most uncompromising of sports and through the wonderful excesses of skill and character, he had become the most famous athlete in the world. He was also known for his pre-match hype, where he would "trash talk" opponents, often with rhymes.In 1999, Ali was crowned "Sportsman of the Century" by Sports Illustrated and "Sports Personality of the Century" by the BBC.