Last week, the tennis world was lucky enough to witness another highly anticipated matchup: the United States’ Serena Wil­liams and Russia’s Maria Sharapova in the quarterfi­nals of the Australian Open. The pair are undoubtedly the world’s most celebrated female tennis players both on and off the court, and fans witnessed the two stars face off in another competitive matchup. Aside from the excitement and anticipation of the matchup and the Austra­lian Open as a whole, de­bate over Sharapova’s rank­ing as the highest-endorsed female athlete in the world resurfaced for the first time since it began last fall. Sharapova has a host of sponsors, including Nike, Porsche and Tag Heurer, whose 2015 endorsements totaled over $23 million last summer. In comparison, Serena Williams amassed an estimated $13 million in the same period, with Nike, Gatorade and Chase head­lining her own collection of sponsorships.

The disparity between the two is especially in­teresting because Wil­liams’ professional career is unquestionably supe­rior to Sharapova’s. Wil­liams’ career prize money is more than double that of Sharapova, which speaks to Williams’ dominance both in her rivalry with Sharapo­va and within women’s tennis as a whole. The duo have competed against one another 21 times, with Wil­liams besting Sharapova in all but two outings. Fur­thermore, in her career, Williams ranks third of all time in Grand Slam titles with 21 and has 69 career titles to her name, while Sharapova has five Grand Slam titles of her own and 35 career titles. Why Sharapova garners nearly double the endorsements Williams gets and has been the highest-paid female athlete in the world for 11 consecutive years is as baffling as it is troubling.

Granted, marketability is by no means an adequate measure of the talent of a given athlete. For example, Kobe Bryant made over $26 million this past year from endorsements, de­spite playing the worst basketball of his career in recent seasons and being on the verge of retirement. Similarly, Tiger Woods received over $50 mil­lion in endorsements last year, despite being currently ranked the 436th best golfer in the world. However, despite their recent decline, both Bryant and Woods are largely considered to be the greatest athletes of all time in their respective sports, meaning their mar­ketability has largely remained intact. Michael Jordan’s subsidiary brand of Nike is a great example of sports icons remaining marketable long after their careers end.

However, Sharapova has never been considered to be an all-time great in women’s tennis, whereas Williams is largely considered the greatest of all time and is still far from retirement. Considering that Canadian tennis player Eugenie Bouchard was named the most marketable athlete in 2015 after winning only one title in the pre­vious year, and considering her los­ing record in the months after, there seems to be a tragic pattern inherent in the women’s sports market. What do Bouchard and Sharapova have in com­mon? They’re both blond-haired, aes­thetically pleasing Caucasian women in their twenties.

In 2015, Williams was the only woman of color ranked in the top 10 highest-paid female athletes in the world. While every single athlete in the top 10 is accomplished and deco­rated in her own right, at first glance it is apparent that many of these women have a market appeal that extends be­yond their sports performance, which is backwards. While it may not bother Williams much, the fact that some athletes will make more money than others based on physical appearance rather than skill is just plain wrong. Inherent in men’s and women’s sports is the notion that certain body images will sell better than less conventional ones.

With regard to women’s tennis, this means that aesthetically pleasing Caucasian players will inevitably make more money off the court than their non-white counterparts, which is an outdated and biased mode of thought. While racial barriers are being broken down every day by more and more athletes of color participating in what are predominately white sports (ten­nis and golf ), this represents only half the battle. The latter half must be ad­dressed by the companies that endorse athletes.

Just because something will sell doesn’t necessarily mean it will sell for the right reasons.