Serena Williams

Serena Williams of the U.S. serves during her women's singles match against Silvia Soler-Espinosa of Spain at the China Open tennis tournament in Beijing...Serena Williams of the U.S. serves during her women's singles match against Silvia Soler-Espinosa of Spain at the China Open tennis tournament in Beijing September 29, 2014.

Petar Kujundzic/Reuters

Serena Williams of the US serves during her singles match against Spain’s Silvia Soler-Espinosa at the China Open tennis tournament in Beijing on Monday.

Serena Williams of the U.S. serves to Daniela Hantuchova of Slovakia during their women's singles match at the Australian Open 2014 tennis tournament in Melbourne...Serena Williams of the U.S. serves to Daniela Hantuchova of Slovakia during their women's singles match at the Australian Open 2014 tennis tournament in Melbourne January 17, 2014.

Jason Reed/Reuters

Serena Williams of the US serves to Daniela Hantuchova of Slovakia during their women’s singles match at the Australian Open 2014 tennis tournament in Melbourne. Williams won 6-3 6-3. Read more

Williams of the U.S. serves to Cibulkova of Slovakia during their women's singles match at the Brisbane International tennis tournament in Brisbane...Serena Williams of the U.S. serves to Dominika Cibulkova of Slovakia during their women's singles match at the Brisbane International tennis tournament in Brisbane, January 2, 2014. REUTERS/Jason Reed

Jason Reed/Reuters

Serena Williams of the US serves to Dominika Cibulkov√° of Slovakia during their women’s singles match at the Brisbane International tennis tournament. Read more

Spectators hold umbrellas to shield from the sun as they watch a match between Serena Williams of the U.S. and Francesca Schiavone of Italy at the China Open tennis tournament at the National Tennis Stadium in Beijing, China Tuesday, Oct. 1, 2013.

Andy Wong/AP

Spectators hold umbrellas to shield from the sun as they watch a match between Serena Williams of the US and Francesca Schiavone of Italy at the China Open tennis tournament at the National Tennis Stadium in Beijing, China. Read more