She is indeed the world No. 1. Germany's Angelique Kerber took over as No. 1 from Serena Williams in September.
She is indeed the world No. 1. Germany's Angelique Kerber took over as No. 1 from Serena Williams in September.
Alexander Hassenstein/Getty Images Europe/Getty Images For Porsche
Kerber began the year by winning the Australian Open final over Williams to open her grand slam account. Williams won their rematch in the Wimbledon final but Kerber won the US Open after the American lost in the semifinals.
Kerber began the year by winning the Australian Open final over Williams to open her grand slam account. Williams won their rematch in the Wimbledon final but Kerber won the US Open after the American lost in the semifinals.
PAUL CROCK/AFP/AFP/Getty Images
Simona Halep began the year slowly but picked up steam, especially after the French Open. The Romanian made the final in Singapore two years ago, losing to Williams.
Simona Halep began the year slowly but picked up steam, especially after the French Open. The Romanian made the final in Singapore two years ago, losing to Williams.
GREG BAKER/AFP/AFP/Getty Images
Garbine Muguruza won the first grand slam of her career at the French Open by defeating Williams. Since that time, however, the Spaniard has struggled.
Garbine Muguruza won the first grand slam of her career at the French Open by defeating Williams. Since that time, however, the Spaniard has struggled.
MARTIN BUREAU/AFP/AFP/Getty Images
Agnieszka Radwanska, a perennial fan favorite due to her different game style, was unable to win her first major this year. But the Pole is the defending champion in Singapore.
Agnieszka Radwanska, a perennial fan favorite due to her different game style, was unable to win her first major this year. But the Pole is the defending champion in Singapore.
Michael Dodge/Getty Images AsiaPac/Getty Images
Karolina Pliskova was the player who upset Williams at the US Open en route to a maiden grand slam final. The Czech leads the women's tour in aces.
Karolina Pliskova was the player who upset Williams at the US Open en route to a maiden grand slam final. The Czech leads the women's tour in aces.
Elsa/Getty Images North America/Getty Images
Madison Keys, like Pliskova, possesses a huge serve and groundstrokes. In Williams' absence, the 21-year-old will lead the US. She was consistent at the grand slams, reaching the fourth round at all four.
Madison Keys, like Pliskova, possesses a huge serve and groundstrokes. In Williams' absence, the 21-year-old will lead the US. She was consistent at the grand slams, reaching the fourth round at all four.
TIMOTHY A. CLARY/AFP/AFP/Getty Images
Dominika Cibulkova wasn't able to make the year-end championships in 2014, despite the Slovakian beginning the campaign by making the Australian Open final. Cibulkova rebounded in 2016, winning three titles and making three other finals.
Dominika Cibulkova wasn't able to make the year-end championships in 2014, despite the Slovakian beginning the campaign by making the Australian Open final. Cibulkova rebounded in 2016, winning three titles and making three other finals.
Clive Brunskill/Getty Images North America/Getty Images