With Serena Williams and Maria Sharapova missing through injury and suspension respectively, the 2016 WTA Finals look to be wide open.
World number one Angelique Kerber and defending champion Agnieszka Radwanska head the eight-strong field in Singapore, with the action set to get under way on Sunday.
Here we look at how each of the players have fared on the WTA Tour so far this season.
A year that started with a maiden grand slam title at the Australian Open will end with Kerber sitting top of the world rankings. The German also reached the final at Wimbledon and the Olympics in Rio de Janeiro, before wrapping up her second grand-slam crown by beating Karolina Pliskova at the US Open. That run at Flushing Meadows saw Kerber reach the rankings summit, ending Serena Williams' record-equalling stint of 186 weeks at world number one. Kerber has reached the Finals on three previous occasions, but has never made it beyond the round-robin stage. Kerber lines up in the Red Group, alongside Simona Halep, Madison Keys and Dominika Cibulkova.
Halep's season got off to a slow start as breathing problems hindered her progress, suffering a shock first-round defeat to qualifier Zhang Shuai in Melbourne. Halep showed glimpses of her past form to reach the fourth round of the French Open before making the last eight at both Wimbledon and the US Open. The Romanian picked up three WTA titles over the year, winning the Madrid Open in May and in Bucharest and Montreal in July. Halep was the third player to qualify for the Finals on September 29 and will be looking to go one better than her final appearance in 2014.
Finals debutant Keys made her break into the world's top 10 this year, reaching the final at two Premier 5 tournaments. The American lost to Williams in Italy before allowing Halep to get the better of her in Canada, but Keys is making notable strides and chalked up the second Premier title of her career with victory over Barbora Strycova in the Aegon Classic in June. Keys reached the fourth round at each of this year's grand slams and finished fourth in the Olympics.
Cibulkova is another new face at the Finals and her road to Singapore has been one of the stories of the season. An Achilles injury followed by a poor run of form saw the Slovak slip as low as 66th in the world rankings. A first final in 22 months came in February this year, before victories in Katowice and Eastbourne further signalled a return to form. The 27-year-old then reached the quarter-finals at Wimbledon, the final at the Wuhan Open and triumphed in Linz, achieving a career-high ranking of eight.
Defending champion Radwanska reached the semi-finals in Melbourne, but failed to make it beyond the fourth round in the remaining three slams of the year. That said, Radwanska has collected three WTA titles in 2016, including a second China Open crown, which saw her become the fourth active player with three Premier Mandatory wins to their name. It was during the tournament in Beijing that Radwanska's place at this year's Finals was secured.
Pliskova and Radwanska qualified for the Finals at the same time, with the former having reached a maiden grand-slam final this year. Although she ultimately lost the US Open to Kerber, Pliskova has enjoyed her share of success in 2016 with wins at the Nottingham Open and Cincinnati Open - two of five finals reached over the course of the year. Pliskova had never previously won a Premier 5 event and will be making her first appearance at the season-ending showpiece.
The highlight of Muguruza's season was a maiden grand-slam triumph at the French Open, but the rest of the year failed to live up to that high standard. After losing the opening set of her campaign at Roland Garros, Muguruza won her next 14 in succession to wrap up the title, including a straight-sets victory over Williams in the final. That proved to be the Spanish player's only title of any description this season, so she will be hoping to improve on her semi-final showing in Singapore last year to end the year on a high.
Kuznetsova was the last player to book her Finals berth by cruising to victory over Daria Gavrilova in the Kremlin Cup final on Saturday. Kuznetsova needed the win to deny Johanna Konta her place in Singapore and the Russian snuck into the top eight with a 6-2 6-1 triumph, defending the title she first won last year. The result saw Kuznetsova reach the Finals for the sixth time, but first since 2009. Kuznetsova had previously won in Sydney in January.