One Number Favors Maria Sharapova In Rivalry With Serena Williams

Serena Williams and Maria Sharapova will meet for the 21st time in the quarterfinals of the Australian Open. Getty Images

We get the dream matchup of the WTA Tour's two biggest stars in the quarterfinals of the Australian Open. But the head-to-head numbers between Serena Williams and Maria Sharapova are downright nightmarish for Sharapova.

In 20 meetings, Sharapova has just two wins, most recently in 2004. We've seen two U.S. presidents and three popes since then.

In the meantime, Williams has won 17 straight over her Russian "rival" and racked up 15 of her 21 major titles. In 2015 alone, Williams topped Sharapova twice in majors without dropping a set.

So what could possibly be different this time around? Belinda Bencic, who beat Williams last summer and lost to Sharapova in the fourth round of the Australian Open, points to one thing. "Probably she's serving the best now in this moment,'' Bencic said. "Once she plays Serena, it will be ace, ace, ace, everything. It will be an interesting match.''