Novak Djokovic is a Serbian professional tennis player who has been ranked World No. 1 by the Association of Tennis Professionals (ATP) since 4 July 2011. He has won five Grand Slam singles titles: the 2008, 2011 and 2012 Australian Open, the 2011 Wimbledon Championships, and the 2011 US Open. By winning three Majors in 2011, Djokovic became the sixth male player in the open era to win three Majors in a calendar year. He is the first male player representing Serbia to win a Major singles title and the youngest player in the open era to have reached the semifinals of all four Grand Slam events, separately and consecutively. Amongst other titles, he won the Tennis Masters Cup in 2008 and was on the team which won the 2010 Davis Cup. He also won the bronze medal in singles at the Beijing Olympics in 2008. He has won 11 Masters 1000 series titles placing
Who is the greatest grass court player?