Question: As of May 2017, Anthony Joshua is ranked as the world's best heavyweight by the Transnational Boxing Rankings Board and BoxRec, the second British boxer, after which British professional boxer, to win both a gold medal at the Olympics and a world title by a major professional sanctioning body, as well as being the first British heavyweight to do so?

full_context: Document 1: Tyson Fury: Tyson Luke Fury (born 12 August 1988) is a British professional boxer. He has held the "Ring" magazine heavyweight title since 2015, after defeating long-reigning world champion Wladimir Klitschko. In the same fight, Fury also won the unified WBA (Super), IBF, WBO, IBO and lineal titles, with the victory earning him Fighter of the Year and Upset of the Year awards by "The Ring". Fury was subsequently stripped of the IBF title later that year for being unable to grant a fight against their mandatory challenger, Vyacheslav Glazkov, due to agreeing to a rematch with Klitschko. In 2016, Fury vacated the WBA, WBO, IBO, and lineal titles following an ongoing medical investigation and personal issues and two cancellations of the Klitschko rematch. In August 2016, Fury was ranked by BoxRec as the world's sixth best active boxer, pound for pound.
Document 2: Joe Calzaghe: Joseph William Calzaghe, {'1': ", '2': ", '3': ", '4': "} ( ; born 23 March 1972) is a Welsh former professional boxer who competed from 1993 to 2008. He is a two-weight world champion, having held the unified WBA (Super), WBC, IBF, WBO, "Ring" magazine, and lineal super-middleweight titles, as well as the "Ring" light-heavyweight title. Calzaghe is the longest-reigning super-middleweight world champion in boxing history, having held the WBO title for over 10 years and making 21 successful defences before moving up to light-heavyweight. As his super-middleweight and light-heavyweight reigns overlapped, he retired with the longest continual time as world champion of any active fighter.
Document 3: Chris Eubank Jr.: Christopher Livingstone "Chris" Eubank Jr. (born 18 September 1989) is a British professional boxer. He has held the IBO super-middleweight title since February 2017, having previously held the WBA interim and British middleweight titles between 2015 and 2016. As of July 2017, Eubank Jr. is ranked as the world's second best super middleweight by BoxRec, sixth by the Transnational Boxing Rankings Board, and seventh by "The Ring" magazine. He is the son of former two-weight world boxing champion Chris Eubank.
Document 4: James DeGale: James Frederick DeGale, {'1': ", '2': ", '3': ", '4': "} (born 3 February 1986) is a British professional boxer. He has held the IBF super-middleweight title since 2015, having previously held the British super-middleweight title from 2010 to 2011, and the European super-middleweight title from 2011 to 2012. As of May 2017, he is ranked as the world's best super-middleweight by "The Ring" magazine and the Transnational Boxing Rankings Board, and third by BoxRec. As an amateur, DeGale represented Great Britain at the 2008 Olympics, winning a gold medal in the middleweight division. By later becoming IBF champion, he became the first British boxer ever to have won both an Olympic gold medal and a professional world title.
Document 5: Anthony Joshua: As of May 2017, Joshua is ranked as the world's best heavyweight by the Transnational Boxing Rankings Board and BoxRec, and second best by "The Ring". His knockout-to-win ratio stands at 100%. Joshua is the second British boxer, after James DeGale, to win both a gold medal at the Olympics and a world title by a major professional sanctioning body, as well as being the first British heavyweight to do so. He is also the second boxer, after Joe Frazier, to win a world heavyweight title whilst still reigning as Olympic champion at the top weight.
Document 6: Mike Tyson: Michael Gerard Tyson ( ; born June 30, 1966) is an American former professional boxer who competed from 1985 to 2005. He reigned as the undisputed world heavyweight champion and holds the record as the youngest boxer to win a heavyweight title at 20 years, 4 months and 22 days old. Tyson won his first 19 professional fights by knockout, 12 of them in the first round. He won the WBC title in 1986 after stopping Trevor Berbick in two rounds, and added the WBA and IBF titles after defeating James Smith and Tony Tucker in 1987. This made Tyson the first heavyweight boxer to simultaneously hold the WBA, WBC and IBF titles, and the only heavyweight to successively unify them.
Document 7: Wladimir Klitschko: Wladimir Wladimirowitsch Klitschko (born 25 March 1976) is a Ukrainian former professional boxer who competed from 1996 to 2017. He is a two-time world heavyweight champion, having held the WBA (Super), IBF and WBO titles, as well as the IBO, "Ring" magazine, and lineal titles. A strategic and intelligent boxer, Klitschko is considered to be one of the greatest heavyweight champions of all time. He was known for his exceptional knockout power, utilising a strong jab, straight right hand and left hook.
Document 8: James Obede Toney: James Obede "Hot Ice" Toney ( (1980--) 05 1980 (age (2017)-(1980)-((11)<(08)or(11)==(08)and(30)<(05)) ) ) born in Accra is a Ghanaian professional middle/super middle/light heavy/cruiserweight boxer of the 2000s and 2010s who won the African Boxing Union (ABU) middleweight title, World Boxing Council (WBC) International middleweight title, and Commonwealth middleweight title, and was a challenger for the World Boxing Council (WBC) International middleweight title against Sergey Tatevosyan, and North American Boxing Federation (NABF) super middleweight title, North American Boxing Association (NABA) super middleweight title, and World Boxing Council (WBC) Continental Americas super middleweight title, against Lucian Bute, his professional fighting weight varied from 157 lb , i.e. middleweight to 185 lb , i.e. cruiserweight.
Document 9: George Groves (boxer): George Groves (born 26 March 1988) is a British professional boxer. He has held the WBA (Super) super-middleweight title since May 2017, and previously the European, British, and Commonwealth super-middleweight titles between 2010 and 2014. As an amateur, Groves won the ABA middleweight title twice, in 2007 and 2008.
Document 10: Frank Bruno: Franklin Roy "Frank" Bruno, {'1': ", '2': ", '3': ", '4': "} (born 16 November 1961) is a British former professional boxer who competed from 1982 to 1996. Bruno had a highly publicised and extremely eventful career. The pinnacle of his boxing career was winning the WBC heavyweight title, in what was his fourth world championship challenge. He also held the European heavyweight title earlier in his career. Bruno was one of the most well-loved and recognisable boxers in British history, and faced multiple top-rated heavyweights during his career including two bouts with Mike Tyson and a domestic clash against Lennox Lewis. He won the WBC title in 1995 after defeating Oliver McCall at a packed Wembley Stadium. Bruno was known for his excellent punching power: he won 40 of his 45 bouts and 38 by knockout, giving him a 95% knockout rate from the fights he won; his overall knockout percentage is 84.44%. Like Henry Cooper before him, Bruno has remained a popular celebrity with the British public following his retirement from boxing.
Document 11: Khalid Yafai: Khalid "Kal" Yafai (Arabic: خالد يافعي‎ ‎ ; born 11 June 1989) is a British professional boxer who has held the WBA super-flyweight title since December 2016. As an amateur, he represented Great Britain at the 2008 Summer Olympics and won a silver medal at the 2010 European Amateur Boxing Championships as a flyweight. As of May 2017, he is ranked as the world's fifth best super-flyweight by BoxRec and the Transnational Boxing Rankings Board, and sixth by "The Ring" magazine.
Document 12: Dale Youth boxing club: The Dale Youth boxing club is an amateur boxing club that operates from a gym on the Lancaster West Estate. It successfully nutured dozens of champions including the young Olympic gold medal winner James DeGale and current world champion George Groves (boxer).
Document 13: Oleksandr Usyk: Oleksandr Oleksandrovych Usyk (Ukrainian: Олекса́ндр Олекса́ндрович У́сик ) is a Ukrainian professional boxer who has held the WBO junior heavyweight title since 2016. As of May 2017 he is ranked as the world's best in the division by "The Ring" magazine, the Transnational Boxing Rankings Board, and BoxRec. As an amateur, Usyk won gold medals at the 2011 World Championships and 2012 Olympics, both in the heavyweight division.
Document 14: David Haye: David Deron Haye (born 13 October 1980) is a British professional boxer who has held world titles in two weight classes. He is the first British boxer to reach the final of the World Amateur Boxing Championships, where he won a silver medal in 2001. As a professional he became the first British boxer to become a unified cruiserweight world champion in 2008, winning three of the four major world titles, as well as the "Ring" magazine and lineal titles. In the same year he moved up to heavyweight, and became the WBA champion in 2009 after defeating Nikolai Valuev, who had a world record 9 in height and 99 lb weight advantage on Haye.
Document 15: Roy Jones Jr.: Roy Levesta Jones Jr. (born January 16, 1969) is an American professional boxer, boxing commentator, boxing trainer, rapper, and actor who holds dual American and Russian citizenship. He is a six-time former world champion in four weight classes, having held titles at middleweight, super middleweight, light heavyweight, and heavyweight; and is the only boxer in history to start his professional career at light middleweight and go on to win a heavyweight title. As an amateur he represented the United States at the 1988 Summer Olympics, winning a silver medal in the light middleweight division.
ground_truth: James Frederick DeGale