US Venus Williams (R) and Serena William

Serena (left) and Venus Williams celebrate a point during their women's doubles semifinal. (AFP PHOTO / MARTIN BERNETTI)

Serena (left) and Venus Williams celebrate a point during their women’s doubles semifinal. (AFP PHOTO / MARTIN BERNETTI)

US Venus Williams (R) and Serena Williams celebrate a point against Russia’s Maria Kirilenko and Nadia Petrova during the women’s doubles semifinal match of the London 2012 Olympic Games, at the All England Tennis Club in Wimbledon, southwest London, on August 4, 2012. AFP PHOTO / MARTIN BERNETTIMARTIN BERNETTI/AFP/GettyImages