It's a Czech one-two at the top of the doubles rankings leaderboard - with Katerina Siniakova holding on to her place currently just ahead of Barbora Krejcikova on the top of the pile.
The pair shared the accolade of finishing with the 2018 WTA Year-End World No.1 Doubles Ranking presented by Dubai Duty-Free, having gone into the WTA Finals Singapore as top seeds.
France's Kristina Mladenovic sits joint third with former World No.1 Timea Babos of Hungary; the pair won the Singapore title last year, beating Siniakova and Krejcikova in the final.
Another Czech rounds out the Top 5 - 32-year-old Barbora Strycova.
Australia's Ashleigh Barty is ranked World No.6 as she seeks to follow up her maiden Grand Slam win at the US Open last year.
In the Race to Shenzhen, Samantha Stosur and Zhang Shuai head the list, with Mladenovic and Babos second, and former World No.1 Latisha Chan alongside Chan Hao-Ching in third.
2019 sees the first WTA Finals to be hosted in Shenzhen - the 10th city and second in Asia-Pacific to host the elite tournament, and will do so for the next 10 years.