In a year-end tournament that is supposed to pit the most dominant players of the season against each other, it's only appropriate that the two men who have lapped the rest of the field meet in the final.
Both men have been otherworldly in 2013.
After missing last year's U.S. Open and this year's Australian Open with knee problems, many wondered if Nadal would be the same player upon his return.
All he did was win six of his first eight tournaments before thundering through the French Open in vintage Rafa fashion. All he did was dominate the North American hard-court series, winning in Montreal and Cincinnati before taking home his second U.S. Open title.
All he did was win a career-high five Masters 1000 events. All he did was win a tour-best 10 of 17 total tournaments (counting the current one), making a career-high 14 finals in the process.
All he did was return to No. 1 in the world, churning out an all-around season reminiscent of Djokovic's 2011 or Roger Federer's 2006 (or '05 or '04).
What he has accomplished after his setback has been nothing short of robot-like, stringing together a career year coming off a significant injury like his name was Adrian Peterson.
Then you have Djokovic. You could make an argument that this was the Serb's worst season in the last three years, but that speaks more to his dominance in '11 and '12 than anything else.
He began the year, as has become custom, with a win at the Australian Open, rolling through Stanislas Wawrinka, Tomas Berdych, David Ferrer and Andy Murray—four ATP World Tour Finals qualifiers—in the process.
Although he ran into the buzzsaw that has been Nadal at Roland Garros and in New York, Djoker has responded brilliantly, winning at Beijing, Shanghai and Paris before continuing his domination at the O2 Arena in London. Currently, he has ripped off 19 straight wins, including a straight-setter over Rafa in Beijing.
Put it all together, and Djokovic has six titles and eight finals appearances in 15 tournaments, putting him head and shoulders above anyone else for the title of second-best player in 2013.
Who will win?
Now, here we are, with the only grand finale that really makes sense: with the two guys who have won three of the four majors, won eight of the nine Masters 1000 events and put on some of the most scintillating matches of the year.
With one guy who has been transcendent, and another who has been just slightly less transcendent.
And we wouldn't have it another way.