Serena Williams solidified her No. 1 ranking by defending her title at the 2013 WTA Championships. Her seemingly insurmountable 5,046 points lead in the WTA rankings reflects the gap between her game and that of the rest in the field.
Williams is clearly the top player. However, there is some serious shifting in the Power Rankings amongst the rest of the Top 10.
Since the U.S. Open, we've seen Li Na, Jelena Jankovic and Petra Kvitova surge. Meanwhile, Maria Sharapova, absent with an injury, became a none factor. Victoria Azarenka, who entered the year ranked No. 1, is mired in a slump.
Most of the names in the Top 10 remain the same. But the Power Rankings have changed.