Novak Djokovic is the man to stop at the ATP World Tour Finals starting in London on Sunday.
The world number one is unquestionably the form player and man to beat heading to London. Djokovic is unbeaten since Cincinnati, winning the US Open and titles in Beijing, Shanghai and Paris since then. The brilliant Serbian will take some stopping, holding a 78-5 win-loss record this year and having won three consecutive London titles.
Murray has an eye on the Davis Cup World Group final, which is being played on clay in Belgium at the end of November. The Brit is still capable of challenging, having impressively reached the final in Paris before losing to Djokovic. He has enjoyed a good run since Flushing Meadows.
Aside from winning Basel for a seventh time, Federer has endured a difficult run since his loss in the US Open final. The Swiss 17-time grand slam champion and last year's London runner-up made earlier-than-expected exits in Shanghai and Paris, losing to John Isner in the last 16 in France.
Wawrinka has been in mixed form since winning the French Open, but at his best can contend. The Swiss star won the title in Tokyo in October and made a run to the last four at the Paris Masters, where he managed to take a set off Djokovic before losing the third 6-0.
The star Spaniard appears to be returning to some of the form that saw him win 14 grand slam titles. Nadal made finals in Beijing and Basel, the last four in Shanghai and quarter-finals in Paris. His confidence has received a boost, but he still has another level to go to if he is to test Djokovic.
Berdych has claimed two titles late in the year - winning in Shenzhen and Stockholm before being edged by Djokovic in the Paris quarters. The Czech needs to produce consistently against the world's best and that has been a challenge this year. Berdych holds a 3-11 record against the top 10 in 2015.
The consistent Spaniard has been his usual self to finish the campaign. Ferrer claimed title wins in Kuala Lumpur and Vienna while reaching the semis in Beijing and Paris. He is another to have battled against the top 10 throughout his career, and this year (3-8 win-loss) has been no different.
A back injury has threatened to see Nishikori sidelined from the season-ending event, having retired in his previous match - a loss to Richard Gasquet in Paris. The Japanese star has a 53-14 win-loss record this year, but has suffered defeats to Benoit Paire, Kevin Anderson and Gasquet late in 2015.