Yesterday tennis player Novak Djokovic went on record challenging the equal prize pay standard in the sport citing, prize money should be “fairly distributed” based on “who attracts more attention, spectators and who sells more tickets”.  This comes after the shocking statement from Raymond Moore, 69, a former player from South Africa, who said: “If I was a lady player, I would go down every night on my knees and thank God that Roger Federer and Rafa Nadal were born, because they have carried this sport. They really have.” This prompted Billie Jean King, who co-founded the WTA Tour and won 12 Grand Slam singles titles, to  tweet:

But are they right? Are women tennis players overrated and overpaid? Should women stop expecting equal pay for performance? Ok, maybe it is difficult to generalize this argument to all industries but we can examine it in the world of tennis. In sport high salaries are paid to only those who are part of extremely wealthy franchises. They are paid because they produce billions in profits for the owners of the teams as well as for other businesses that rely on the team’s success. This is a multi billion dollar industry involving endorsements, media rights, fanfare etc., and the main players in this are the athletes who are rewarded with fat pay checks in return for their contribution. So in this case one can argue that the equal pay standard for the Tennis prize pay, applied since 2007, is a fair practice etching away at gender barriers in sport.

And according to statistics the Women’s tennis is attracting a growing viewership and new endorsements to the world of tennis. Male athletes still claim the majority of athlete endorsement deals (which in turn equates to a significantly higher overall salary), but women are broadening brand interests from fashion, beauty, investment and music companies. And as more women increase their influence, more female athletes are signing endorsement deals with new brands creating more opportunities for the sport and the athletes than ever before. Here are some numbers:

• Excluding Grand Slams, 395 million watched WTA Premier events and finals on TV and digital, compared with 973 million for ATP events
• In 2015, the Wimbledon men’s final attracted a peak audience of 9.2 million viewers, compared with 4.3 million for the women’s final.
• At the US Open, the men’s final drew 3.3 million viewers, compared with 1.6 million for the women’s final
• However, in the previous two years, the US Open women’s final was watched by more viewers than the men’s.
• Men’s finals generally garner more ticket sales than women’s finals. However, in 2015, tickets for the US Open women’s final sold out before the men’s
• Djokovic earned $21m (£14.5m) in prize money last year, compared with Williams’ $10.5m (£7.3m), but the two 10th highest earners, Jo-Wilfried Tsonga and Roberta Vinci, both earned $2.2m (£1.5m).
• Men play five sets at the Grand Slams. At all other times both men and women play three sets.
• In the past the long-term tennis endorsments for men have been with Nike, Mercedes Benz, Rolex, Peugot and Seiko
• Since 2015 new tennis endorsements specifically for the female athletes include Oriflame, Danske Invest, Proactiv, OPI and Sony Ericsson

The statistics are an anomaly in Women sports.  The numbers for women Basketball, football, baseball, hockey, lacrosse, volleyball, poker, NASCAR, and anything else you can think of pale in comparison to the popularity of the WTA tour.

Last year only three women cracked the Forbes 100 Highest Paid Athletes list, and all three—Maria Sharapova, Li Na and Serena Williams—were tennis players. It’s not that tennis is more lucrative than other professional sports: only three male tennis players made the list too. Women’s tennis is just more popular than any other women’s sport.

The truth of the matter is that thanks to players like Sharapova, Williams and Na the tennis sport will earn more endorsements and TV face time, refreshing the world of tennis in a fashion, translating to higher profits and better earnings for every tennis athlete, so they should be paid equally.