Many have tried but only few were chosen...
World Champion is the top achievement for any sport or contest reached by individual in the world in a particular field.
Roger Federer (born 8 August 1981) is a Swiss professional tennis player who, as of May 2013, is ranked World No. 3 by the ATP. Federer has continuously ranked as one of the top 3 in the ATP rankings for the last decade (since July 2003). Many commentators and former and current players have called Federer the greatest tennis player of all time.
He holds several men's world records of the Open Era: holding the World No. 1 position for 302 weeks overall; a 237-consecutive-week stretch at the top from 2004 to 2008; winning 17 Grand Slam singles titles; reaching the finals of each Grand Slam tournament at least five times (an all-time record); and reaching the Wimbledon final eight times. He is one of seven men, and one of four in the Open Era, to capture the career Grand Slam, and one of three (with Andre Agassi and Rafael Nadal) to do so separately on clay, grass, and hard courts. Federer also shares the Open Era record for most titles at the Australian Open with Agassi and Novak Djokovic (4), at Wimbledon with Pete Sampras (7) and at the US Open with Jimmy Connors and Sampras (5). Federer's ATP tournament records include winning six ATP World Tour Finals, playing in the finals at all nine ATP Masters 1000 tournaments (a record shared with Djokovic), and having won the most prize money of any other player in history, with over $75,000,000.
Credit to WIKI