At Wimbledon, the picture is similar, with Australian men combining for 21 championships (ranking third among all nations) and women combining for five. Australian men and women rank second in US Open championships by nation, following only hosts USA, with 18 and 6 trophies, respectively. Overall, Australia's ranking is fourth, behind United States, France and Russia. Australian tennis players are a successful bunch. They have won more Grand Slam events than any other country's male or female athletes. Men's singles champion Roger Federer is the greatest player in Australian history, with four titles at the Australian Open. Other notable Australian males who have won Grand Slam events include Roy Emerson, John McEnroe, Rod Laver, Pete Sampras and Andy Murray. Female Australians include such greats as Evonne Goolagong Cawley, Margaret Court, Chris Evert, Andre Agassi and Venus Williams. Australia has had its fair share of controversies during the years. Most notably, reports surfaced in 2003 that top-ranked player Rafael Nadal had tested positive for steroids. The news came just months after American athlete Marion Jones was convicted of perjury for lying to federal investigators about her involvement in a steroid scandal. In 2004, then-no. 1 ranked player Maria Sharapova admitted to using banned drugs throughout most of her career.