Rafael Nadal and Kevin Anderson go head to head at the US Open on Sunday — and the winner will pocket $3.7 million

In the sport of tennis, rank doesn’t always equal wealth.Clive Brunskill/Getty

Rafael Nadal, the Spanish tennis player currently ranked No. 1 in the world, has advanced to the men’s final of the US Open Tennis Championships this week in New York City. He’ll play No. 28 Kevin Anderson of South Africa on Sunday.

The championship title winner will take home $3.7 million, while the runner-up will walk away with $1.825 million. The United States Tennis Association is handing out a total of $50.4 million during the 2017 US Open — the largest purse in tennis history.

Nadal holds 73 overall titles — including 15 Grand Slams, which award the most prize money. The 31-year-old has been playing professionally since 2001 and is a two-time winner of the US Open.

Though Nadal’s dominance in the sport is indisputable, his total career earnings — about $86.3 million — are not a reflection of his current top-player status, at least when compared to his rivals.

The Association of Professional Tennis (ATP) is responsible for ranking players, measuring their performance in the Grand Slam, Masters, and a handful of other tournaments throughout the year. A player’s placement in those tournaments adds up to ultimately determine their numbered world ranking.

But in the sport of tennis, rank doesn’t always equal wealth.

Serbia’s Novak Djokovic, who’s ranked No. 5, is currently the highest-paid tennis player in the world, with a total of $109.8 million in career winnings. Roger Federer, the Swiss man who sits at No. 3, has won $107.7 million in prize money.

Novak Djokovic shakes hands with Roger Federer after winning the semifinal match at the 2016 Australian Open.Michael Dodge/Getty

Tournament purses are consistently increasing, and more wins in recent years for Djokovic, who’s been playing professionally since 2003, has likely added up to a higher total sum. In fact, the Serbian earned a record-breaking amount of prize money in one season in 2015 when he pocketed $20 million, winning three of the four Grand Slams that year.

On-court payouts are just one factor contributing to the multi-million dollar net worths of the top tennis players.

Nadal has earned $31.5 million from endorsements like Nike, Babolat, and Kia Motors, so far in 2017, according to Forbes.

The deals are even more lucrative for Federer, who earns nearly $60 million a year from partnerships with Wilson, Credit Suisse, and Nike, and luxury brands Mercedes, Rolex, Lindt, and Moet & Chandon. He also commands fees up to $2 million for exhibitions and events.

Djokovic isn’t far behind. The Serbian has earned $37.6 million off-court this year, endorsing brands like Seiko watches and Adidas. Earlier in 2017, he traded in his signature Uniqlo apparel for a new deal with Lacoste.