A truncated tennis season draws to a close with the last edition of the Nitto ATP Finals at London's O2 Arena.
Here, PA Sport picks out five talking points for the event.
A sad farewell
It is easy to forget that bringing the tournament to The O2 in 2009 was deemed a big risk. But close to three million fans made the journey to Greenwich during the first 11 years, making it one of the most successful tennis events in the world. The ATP had hoped to go out with a bang, especially given it is also the 50th anniversary of the tournament, but instead coronavirus means no fans are allowed and all fireworks must be reserved for the TV coverage.
Djokovic chasing another record
Having ensured he will equal Pete Sampras by finishing a season ranked world number one for the sixth time, Djokovic can match Roger Federer's mark by adding title number six at the ATP Finals. He won four titles in a row in London from 2012 to 2015 but has fallen short on his last four visits. He nevertheless begins the event as the favourite and will want to end the year on a high after his heavy French Open final defeat.
Nadal tries again
Nadal's first appearance in the tournament came back in 2006 but it remains the biggest title he has never won. He has reached the final twice, most recently in 2013, while injury has prevented him from taking part on five occasions. Indoor hard courts are the surface he finds most challenging – the Spaniard has frequently made the case for having a turn on clay – and it would be something of a surprise if he manages to break his duck this time given the prowess of many of his rivals on the surface.
Next gen success
Dominic Thiem finally struck a grand slam blow for the 20-somethings by winning the US Open – albeit with Nadal and Roger Federer absent and Djokovic sabotaging himself. The ATP Finals has been a more fruitful hunting ground, with Alexander Zverev beating Djokovic to win the title in 2018 and Tsitsipas battling past Thiem in a epic final 12 months ago. They will be among the favourites again, while Daniil Medvedev returned to form impressively by beating Zverev to win the Paris Masters last weekend.
Salisbury flying home flag
There is only one British player competing this year – doubles specialist Joe Salisbury, who qualified with his American partner Rajeev Ram. They made their debut last season, falling in the group stages, but should have high hopes of going further this time. The pair won their first grand slam title at the Australian Open in January and have established themselves as one of the world's top teams. No British player has ever reached the doubles final at the event.