#3 - Kiki Bertens
Prior to Simona Halep's shock injury troubles, nobody would have expected Kiki Bertens to play the WTA Finals in 2018. She strung a few strong weeks here and there but lacked overall consistency.
The Dutch 26-year-old has a losing H2H record against all of her group-mates - Kerber (1-2), Osaka (1-2) and Stephens (0-1). Coming in as top seed Simona Halep's last-minute replacement, Bertens could overturn the losing H2H against all of them.
Her topsy-turvy form this season has been a spot of bother, but it also adds an unpredictable element to her game. She won Cincinnati and Korean Open, but the month of October hasn't been too fruitful. Now, with the sudden spot at the WTA Finals, Bertens should play at her full potential to make it count, because with all the big hitters coming up (who barely missed the qualification), it might be her best chance.
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