Rafael Nadal has a very handy lead atop the ATP rankings, but history suggests it will be Roger Federer taking his mantle when 2017 comes to a close.
With victory over his long-time rival in the Shanghai Masters final on Sunday, Federer edged closer to Nadal in the race for the year-end No.1 ranking.
However Nadal is still leading by 1960 points with just three events remaining this year.
But there are still 3000 points up for grabs in Basel, Paris and at the ATP Finals in London, and Federer can certainly take advantage of the faster courts on offer to gain some serious ground on Nadal.
Nadal only needs to make the final in each event to clinch the No.1 ranking, even if Federer beats him in all three.
But the Spaniard, who wore a bandage on his knee in Sunday's final, recently suggested he's not sure if he'll play in Basel next week.
"I don't know, I need to think about it. No, no, I cannot (decide right now). I cannot tell you," he said.
On Sunday Federer conceded that winning back the top spot is a long shot and instead his focus is on winning the ATP Finals.
"London is my priority now and I really want to win the World Tour Finals," Federer said.
"Everything that comes now is a bonus after the year that I've had.
"Finishing as No.1 is a long shot, and I don't think it will happen but if I play like this, who knows? Maybe I will get close again."
However history is well and truly on the Swiss Maestro's side.
Federer is a seven-time champion in his home tournament in Basel and has won the ATP Finals six times, although he only has one title in Paris.
But in complete contrast, Nadal has never tasted success in any of the three.
Federer also has a whopping 22 indoor titles, compared to just two for Nadal, and all three events will be played indoors.
Federer hasn't yet decided whether to play in Basel next week, but he may be swayed by the temptation to capitalise on a massive Nadal weakness.
"The year has been long, yes, but I haven't played that much, to be honest," the 19-times grand slam winner said on Sunday.
"The body is fine. I'm going to reassess everything after I come home to Switzerland tomorrow. I will get together with my team and just come up with a plan, set the priorities, see how my body feels tomorrow.
"But so far I'm good, I'm happy I'm feeling this way. It's been a tough week - five straight matches is always a test and a challenge for anybody's body, especially with the pressure rising throughout the event."
TURNING THE TABLES: How Federer reversed Rafa's rivalry domination
Federer claimed his 94th career title in Shanghai, pulling him level alongside Ivan Lendl at second on the all-time list, with both men trailing the 109 of Jimmy Connors.
He won his 350th match at the Masters 1000 level as he claimed his 27th trophy in the elite series.
The 36-year-old Swiss now owns six titles from 2017 - the same as Nadal.