Caroline Wozniacki is known for her exceptional defense, but the former No. 1 won the WTA Finals with what seemed to be a newfound emphasis on offense.
The 27-year-old has been on a roll in Asia, winning her first title of the season in Tokyo and then taking the biggest title of her career at the WTA Finals. She reached eight finals in 2017.
Though not known for her serving, Wozniacki's delivery led the tournament during the round-robin part of the competition. She won more than 69 percent of the points off her first ball and more than 50 percent off her second, and even had the most aces. Wozniacki also held more than 82 percent of the time, again the highest mark in the round-robin stage.