Roger Federer and Rafael Nadal have created one of the greatest rivalries in sports history. While their epic struggle has been driven by the contrast in their styles of play, they often seem intertwined -- so much so that they provided the tennis lexicon with a new word, "Fedal."
These men are more than rivals. They're collegial champions and friends, ambassadors and advertisements for the game. The over-30 idols staged a joint comeback this year, battling tooth, nail and press clips to sweep all four Grand Slams and end the year atop the ATP rankings (Nadal at No. 1, Federer right behind).
Theirs was a tennis feel-great story, but it also sent a message. Andre Agassi, now coaching Novak Djokovic, told ESPN.com: "They are redefining what people are capable of and what career longevity actually means."
But the Year of Fedal did leave one intriguing question hanging for fans. Put simply, "Who had the better year?" If the ATP had an MVP for 2017, would the honor go to muscular Nadal or meteoric Federer? Let's go through the details and pick one:
Overall record: Advantage, Federer
The magic number when it comes to winning percentage in tennis is .900, or a 90 percent success rate. Federer once again cleared the highest bar with a WP of .912, based on a match record of 52-5.
Nadal exposed himself to losses far more often, but unlike Federer, he played a healthy schedule on all surfaces. He finished 67-11 for a winning percentage of .859. Nadal's age (31, compared to Federer's 36) probably had something to do with his heftier workload.
The sheer volume of matches Nadal contested also had an enormous upside. It earned him the year-end No. 1 ranking. That counts for a lot, but one other detail swings the pendulum to Federer's side for good: He made eight finals and won seven. Nadal won six finals and lost four -- three of them to Federer.
Quality titles: Advantage, Federer
Two of Nadal's six titles were majors (French Open and US Open), and he added ATP Masters 1000 wins at Monte Carlo and Madrid. Federer saw Nadal, and raised him one Masters title. Fed won the Australian Open, Wimbledon and three Masters. He completed the demanding "Sunshine Double" when he won at Indian Wells and Miami, beating Nadal at both places.
"This is where it all started for us in 2004 when you were a little boy who grew into a big man and strong man," Federer said after he hammered Nadal 6-3, 6-4 in the Miami final. "We have had some epic matches over the years, which I didn't always enjoy, but mostly [did]."
Grand Slam performance: Advantage, Nadal
Jo-Wilfried Tsonga, one of Fedal's perpetually disappointed rivals, put it best when he remarked: "We all have in mind that Roger now has won 19 majors and Rafa won 10 times Roland Garros almost in a row, which is just unbelievable. What can we say about it except, magnifique?"
Federer recorded 18 straight Grand Slam match wins before he took his first -- and only loss -- to Juan Martin del Potro in the quarterfinals of the US Open. But Federer skipped the clay season and Roland Garros. He was forced to five sets five times -- four of them in Australia. Nadal was 23-2, with four five-set matches, but two were tough to digest -- the Australian Open loss to Federer and that five-set battle Nadal lost to Gilles Muller in the fourth round of Wimbledon.
The average ranking of Nadal's 25 Grand Slam opponents was No. 42, while for Federer it was 57. Federer had the easiest run in the Australian, where his opponents' rankings averaged out to No. 87, while the figure for Nadal was No. 19.
Nadal gets the endorsement here because he played all the majors and won more matches. Federer's decision to skip clay in order to prepare for Wimbledon was understandable, but in tennis, showing up counts.
Consistency: Advantage, Nadal
Being the King of Clay is well and good, but it's pretty easy to go from prince to pauper when only 30 percent of tour events are staged on dirt. Nadal piles up wins regardless of surface -- something Federer did not do in 2017 because of his decision to bypass the clay segment.
Only one tournament (Shanghai Masters) had a faster Court Pace Index this year than the Australian Open (CPI, 42). Federer loved the fast courts; Nadal, not so much.
Federer was unable to exploit the 35.7 CPI at the US Open to survive past the quarterfinals, while Nadal won the event despite being outside his comfort zone. The courts in Flushing Meadow were slower than those in Melbourne but still faster than all but two of the outdoor Masters 1000 events.
As Simona Halep said of Nadal at the WTA Finals: "I always love the way he's on court. Every match that he wins is like the first match of his life and the last one. So this is impressive." It's also remarkably consistent.
Head-to-head against the elite: Advantage, Federer
Federer won all four meetings with Nadal in 2017, which cut Nadal's lead in the career rivalry to 23-15. Federer also outdueled Nadal in two critical finals, the Australian Open and Miami Masters. What's worse for Nadal is that Federer basically crushed him in three of four meetings in 2017. It helped Federer compile a better record against top-10 opposition in 2017. He was 14-2 to Nadal's 12-6.
"The Australian Open was a great match. The others, though, were one-way traffic," Paul Annacone, a Tennis Channel commentator who coached Federer through some of his best years, told ESPN.com. And all that traffic flowed toward Federer.
Impact on the game: Advantage, Federer
It may not be performance-based, but an MVP ideally has an influence on how the game evolves as well as how it is played. There's no doubt that the Laver Cup, pitting a team from Europe against one representing the rest of the world, was a great idea as well as a resounding success. Nadal played in it, but Federer invented it. Whether the event lasts and becomes a staple of the calendar is yet to be seen, but it's off to a terrific start.
While both men are inspirational, Federer brought one additional quality to the table of strivers. He was a 17-time Grand Slam champion, 35 years old, when he decided to change and grow his game by introducing the aggressive elements that shaped his success of 2017.
"I can learn from Roger that at any age you can still learn something in tennis, even if he was perfect before," Halep said. "He showed us that if you believe, and if you work hard, you can get better. So there is no limit, in my opinion, about Roger."
The 2017 MVP belongs to ...
By a nose, Federer is our choice as MVP for this extraordinary year in tennis.