Who CAN Beat Serena?
For Serena Williams to lose her bid for the calendar-year Grand Slam, another player would have to step up and beat her, something that hasn't happened at a major in more than 14 months. While there will be 127 potential candidates for the role of vanquisher, there are few obvious choices. Serena has no rival—no Nadal to her Federer—nor has any one colleague played the burr in her saddle and vexed her. Still, before the making of the U.S. Open draw, here are five potential spoilers.