Wladimir Klitschko is a fighter.
Professional boxing , or prizefighting , emerged in the early twentieth century as boxing gradually attained legitimacy and became a regulated , sanctioned sport . Professional boxing bouts are fought for a purse which is divided between the boxers as determined by contract . Wladimir Wladimirowitsch Klitschko ( Володи́мир Володи́мирович Кличко́ , ; born 25 March 1976 ) is a Ukrainian professional boxer . A strategic and cerebral boxer , Klitschko is considered to be one of the greatest heavyweight champions of all time , as well as among the hardest punching knockout artists in the history of the division ; his strong jab , straight right hand and left hook being his most formidable weapons . Overall , he became the second-longest reigning heavyweight champion of all time , and has the second-most successful title defenses total of any heavyweight boxer with 23 ( including his initial reign as WBO champion ) , behind Joe Louis ( 25 ) and ahead of Larry Holmes ( 20 ) and Muhammad Ali ( 19 ) .