This year's Australian Open marks the 20th anniversary of Serena and Venus' debut in Melbourne. (AP)

What Venus and Serena Williams have achieved for the sport of tennis goes far beyond their titles and prize money. The sisters have changed the look of the game, and their greatest legacy may be proving that tennis isn't just for white children of privilege. 

Just take a look at the recent rise of African-American players. There are now eight African-American women inside the Top 200 including 2017 US Open champion Sloane Stephens, and world No. 17 Madison Keys. Coming up behind them are two talented juniors Coco Gauff and world No. 199-ranked Whitney Osuigwe. 

 
 
 
 
 
 
 
 
 
 
 
 
 

Some things never change

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The Williams effect is not limited to the WTA and to American tennis as there's also the likes of Frances Tiafoe, who played with Serena at the Hopman Cup, and Japan's Naomi Osaka. Both of them have been influenced by the Williams sisters. A recent Times article revealed that Osaka's father, Leonard Maxine Francois, was inspired by Richard Williams' method of relocating and grooming his daughters for tennis. 

 
 
 
 
 
 
 
 
 
 
 
 
 

So honored to appear on the cover of @time . Thank you everyone and I hope you enjoy the story.

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This year marks the 20-year anniversary of Venus and Serena's Australian Open debut. A 17-year-old Venus made the quarterfinals, while eventual seven-time champion Serena fell in the first round. 

As 38-year-old Venus and 37-year-old Serena get ready to begin yet another Australian Open campaign, the bigger picture of what they mean to the sport is more obvious than ever.