Five-time former champion Novak Djokovic is making his 12th appearance at the ATP Finals.
Djokovic finds himself in a group containing six-time champion Roger Federer, two-time Roland Garros runner-up Dominic Thiem and tournament debutant Matteo Berrettini.
In 11 previous appearances in the tournament, Djokovic has failed to get out of his group on three occasions - going 0-3 on his debut in 2007, 2-1 in 2009 and 1-2 in 2011. The Serb has a 35-12 win-loss record at the ATP Finals, with nine of his defeats coming in the round robin stage of the competition, one in the semifinal (2010), and two in finals (2016, 2018).
Only Roger Federer (57), Ivan Lendl (39) and Boris Becker (36) have more wins at the ATP Finals than Djokovic. The Serb however holds the record for most consecutive title triumphs (four), doing so between 2012 and 2015.
Djokovic also holds the record for most consecutive match wins (15) in the tournament (2012 to 2015).
At the 2019 ATP Finals, Djokovic holds a combined 68-57 head-to-head record against the other seven competitors in the tournament, which includes a 26-22 lead over Federer and a 6-3 lead over Thiem. Djokovic is yet to meet Berrettini.
If the World No. 2 Serb gets past the group stage, one of Rafael Nadal, Sascha Zverev, Daniil Medvedev or Stefanos Tsitsipas would be his probable last four opponent.
Djokovic's has split his two meetings with Zverev at the ATP Finals - he won in the round-robin stage of the 2018 event and lost in the final the same year.
Djokovic is 3-2 against Nadal, losing in the round-robin stage to the Spaniard in 2007 and 2010, and beating Nadal in the 2009 round-robin, 2013 final and 2015 semfinal. Tsitsipas and Medvedev are making their tournament debut at the 2019 ATP Finals.
In 2019, Djokovic has lost two of his three meetings with Medvedev, which includes losses in the pair's last two meetings. In three meetings with Tsitsipas in 2019, Djokovic leads 2-1, which includes a win in the pair's last meeting - at the 2019 Paris quarterfinals.
Since his last group-stage exit in 2011, Djokovic has reached the final in all his six subsequent appearances in the tournament. That is exactly what the Serb needs to accomplish again, at the very least, to stay in contention for a record-tying 6th year-end No. 1 finish.
Djokovic trails top-placed Nadal by 640 points in the race for the top spot. In the 10 different scenarios for Djokovic to reclaim the No. 1 position at the end of the tournament, the Serb needs to reach the title round on each occasion.
In the best case scenario for Djokovic, if Nadal pulls out of the tournament or does not win a round-robin match (something Nadal hasn't endured since 2009), the Serb would ensure a record-tying 6th year-end No. 1 (also Pete Sampras) by reaching his 8th final in the tournament.