The 2019 ATP Tour season reaches its climax as the world’s best eight players head to London for the ATP Finals.

This year, the tournament is given an added element of intrigue as if either Rafael Nadal or Novak Djokovic emerge victorious, they will end the year as world number one.

Here’s our preview ahead of the start on Sunday.

Paris win means Djokovic is rightful favourite

Serbian supremo Djokovic must be smarting from the fact he’s been replaced as world number one. He held the accolade for just over a year and despite winning the Paris Masters last time out, he’s been replaced by Nadal at the summit.

It’s been another very good year for 32-year-old Djokovic with five titles, including winning both the Australian Open and Wimbledon. He’s won two of his last three tournaments too and given he’s been victorious at this event five times, it’s hardly surprising to see him as the 6/5 favourite.

The loss of his number one ranking and the fact he can win it back this week will surely act as increased motivation for the Serb and he’s the one they’ve all got to beat. He’s been drawn alongside Roger Federer, Dominic Thiem and Matteo Berrettini in the Bjorn Borg group and he’s just 4/7 to advance to the semi-finals as the group winner.

Young pretender Medvedev can continue fine run

While he’s always been regarded as a future star, it’s hard to think many believed Daniil Medvedev would have risen up the world rankings quite as quickly as he has. The 23-year-old Russian entered 2019 as the world number 16 and hung around that position for large parts of the year before he turned a corner in August, surging into six consecutive finals, three of which he won in Cincinnati, Saint Petersburg and Shanghai.

Medvedev looks to have targeted this event having opted out of tournaments in Moscow and Vienna recently and he looks primed for another bold showing here. He has been beaten by Nadal twice in that run and that’s a slight worry, but given Nadal’s injury worries and the fact the Spaniard has a poor record at this event, he looks worth opposing at 11/2.

The fast court in London will suit Medvedev’s game and bar a poor performance in Paris last time out, he’s been the model of consistency recently, which can’t be said for Djokovic and Federer, as evidenced by their surprise defeats in Shanghai. The Russian, who is in the Andre Agassi group alongside Nadal, Stefanos Tsitsipas and Alexander Zverev, has won 29 of his last 32 matches and looks the best bet to win the trophy at 4/1.

Check out all the latest tennis betting odds at William Hill.