After winning the WTA Championships in her debut, Petra Kvitova, now ranked No. 2, is closing in on the No. 1 ranking. The Czech is only 115 points behind top-ranked Caroline Wozniacki, who has 3,931 points to defend through her title run in Charleston in early April. Kvitova only has 1,257 points to defend during that same stretch. No. 3 Victoria Azarenka also has a shot at the top spot, as she's only 965 points behind Wozniacki and has only has 526 points to defend until Indian Wells in early March. Maria Sharapova, now No. 4, is also in the hunt. She is 975 points behind Wozniacki and has only 350 points to defend until Indian Wells.