Hard to believe, then, that the same three men were the top three seeds when their paths first collided at the ATP Finals back in 2007. Then, it was called the Masters Cup, and was played in Shanghai, and No1 Federer won his fourth year-end title.
This year, the 38-year-old Swiss is seeded third, and has been drawn into the same group as the 32-year-old five-time champion Djokovic, while 33-year-old Nadal, who snatched back the No1 ranking this week, tops the other group.
As if their longevity and consistency needed any further evidence, the same three men have held that top spot between them exclusively since February 2004, aside from a nine-month residency by Andy Murray between 2016 and 2017. Indeed that same quartet are the only men to have held the No2 ranking since 2005.
And as 2019 draws to a close, Federer at 36, Nadal at 33 and Djokovic at 32 are—perhaps not surprisingly—the oldest No1s aside from a 33-year-old Andre Agassi. Timely, then, that one of this year’s groups is named after the American.
However, this year, in the penultimate playing of the event in its 12-year residency at London’s O2, there is certainly a pleasingly youthful contingency alongside the current triumvirate.
While four of the other men who contested that 2007 title have long since retired—the likes of Nikolay Davydenko, Andy Roddick and Fernando Gonzalez—four of the qualifiers this year are age 23 and under, and three of them are debuting at the tournament: 23-year-olds Daniil Medvedev and Matteo Berrettini, and 21-year-old Stefanos Tsitsipas. The fourth young face? He happens to be the defending champion, after winning last year at just 21, Alexander Zverev.
Even so, probably the biggest stories destined to unfold in London will again focus on the old guard, for several reasons.
· Djokovic can reclaim the No1 ranking by the end of the tournament—though he is likely to need to win the title to recoup a 640-point deficit, and if Nadal wins all three round-robin matches and his semi-final, he will be untouchable.
· Nadal is in pursuit of the only big title in tennis that has eluded him.
· Federer is hoping to extend his record number of victories to seven, but Djokovic is aiming to equal him with his sixth.
Schedule: Doubles begin at midday and 6pm, singles at 2pm and 8pm
Doubles final: Sunday, 17 November at 3.30pm; singles final, not before 6pm
Group Andre Agassi—matches begin Monday
Nadal has a 51-6 match run for the season and has qualified for the ATP Finals for a record 15th consecutive year. He was runner-up in 2010 and 2012. He is 11-1 against the rest of his group, with only Tstisipas picking up a win.
 Rafael Nadal
 Daniil Medvedev
 Stefanos Tsitsipas
 Alexander Zverev
Group Bjorn Borg—matches begin Sunday
Djokovic has a 53-9 match record in 2019, has qualified for the season finale for the 13th time, and won five times. He is 26-22 against Federer, 6-3 versus Thiem. Federer is 51-8 for the year.
 Novak Djokovic
 Roger Federer
 Dominic Thiem
 Matteo Berrettini
Alternates: Roberto Bautista Agut, Gael Monfils
· O2 arena holds 17,800
· Total prize money: $9,000,000; undefeated champion can pocket $2,712,000
· Most singles titles: Federer, six, plus four additional finals
· Most singles appearances: Federer, 16 (first in 2002)
· Oldest champion: Federer 30, in 2011
· Youngest champion: John McEnroe, 19 in 1978
· Lowest-ranked champion: No12 David Nalbandian, 2005
· Most match wins: Federer (57)
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BIOGRAPHY: Ethan Hazard
BIOGRAPHY: Daniel Sturridge