Serena's future on her shoulders

— -- She blew through the formidable field in Miami back in March, hacking down Angelique Kerber, Maria Sharapova and Li Na -- the last two her most formidable rivals this year -- in swift succession.

And then the Sony Open champion traveled up the road to Charleston and was stunned in her first match by Slovakia's  Jana Cepelova, the WTA's No. 78-ranked player.

At 32, Serena Williams continues to be the best women's player in the game. Her serve, considered by many the best ever, is still lethal. Her quickness and top-end speed, when she is healthy, remains crackling. In recent years, her fitness and tennis acumen have actually improved.