No matter where or when they play, a Williams-Sharapova match yields high drama. The two renew their rivalry Tuesday in the quarterfinals of the 2016 Australian Open.
Williams has won the last 17 meetings. Sharapova's last win over Williams was in 2004.
Some might debate whether you can still call this a rivalry. But it is, no matter how one-sided the outcomes have been. The stakes, the personalities, the streak and the history, make Williams vs. Sharapova must-see TV.
They are the two biggest names in women's tennis. Fashionistas, entrepreneurs and covergirls, Williams and Sharapova transcend sports.
They are the most visible female tennis players on social media. Sharapova leads all WTA players in Facebook followers. Serena leads all players in Twitter followers, per Quick Top Tens.
Williams has earned just over $74 million in career prize money, more than any woman in the history of sports. Sharapova reportedly earns more endorsement money than any woman in sports, according to Forbes.
It's safe to say that neither Williams nor Sharapova will be lining up at a soup kitchen anytime soon.
So what if Williams owns Sharapova on the court. The longer the streak continues, the bigger deal it becomes. Rafael Nadal has a 23-11 record against Roger Federer, but people still want to see them play because they are among the best in the business.
Williams and Sharapova have been the most consistent players over the past five years. They've won a combined 10 of the last 16 Grand Slams.
For all the hype about "rising stars," and "up and comers," Williams and Sharapova are the two players who continue to find their way into semifinals and finals.
There's stiff competition. At this year's Aussie Open, Victoria Azarenka is expected to provide a better test for Williams. However, Vika's brand is nowhere near in the same neighborhood as Williams and Sharapova.
She can Dab all she likes, but Azarenka has yet to attract the loyal, if not polarizing, gigantic fanbases of Williams and Sharapova.
Azarenka is famous. Sharapova is famous and iconic. Williams is famous, iconic and legendary. Two icons will always cause a commotion.
As soon as the match was set, terms like blockbuster and epic were used to describe it.
There's more than a spot in the semifinals on the line. Williams is trying to win her 22nd Grand Slam title to tie Steffi Graf. Sharapova is trying to overcome a decade of defeats.
Their careers are so intertwined; Sharapova's legacy is tied to her record against Williams. Sharapova's win over Williams at Wimbledon in 2004 propelled her into the spotlight. The losses have haunted her career.
Williams' dominance over Sharapova has backfired. Critics point to it as evidence that she plays in a "weak era."
Six of Williams' wins over Sharapova have come at a Grand Slam; three were in finals. If Sharapova had won even two more of those finals, that would elevate her above Venus Williams, who with seven Grand Slam titles is still second among active women.
While guaranteed a spot in the Hall of Fame, Sharapova has yet to enter the conversation of "all-time greats." That's reserved for those with Slam titles in the double digits.
It's unlikely Sharapova could ever gain an advantage over Williams in the win column. However, if Sharapova were to play spoiler at the tail end of Williams' career, it could change the complexity of the rivalry.
What if she halts Williams' run here, at the French Open or maybe at Wimbledon? That's another reason we watch; for the what-ifs.
We also tune in because they are fun to watch. They hit hard. They scream "C'mon!" Few people on the WTA or ATP World Tour can deliver the death stare like Williams and Sharapova.
So what might be different this time?
Well, Sharapova is serving better than she has in years. She has 52 aces this tournament. Williams has only 25. Sharapova served 21 aces in her fourth-round match against Belinda Bencic.
During her post-match press conference, Sharapova told reporters that she's worked hard to improve her serve. "I think I have made a little bit of a change last year in the stance, but I think everyone always tries to improve things here and there. It's not that big of a deal. We always look to add those few percentages."
Bencic told reporters (via espnW) that Sharapova's serve could be a game-changer. "Probably she's serving the best now in this moment...Once she plays Serena, it will be ace, ace, ace, everything. It will be an interesting match."
After her fourth-round win over Margarita Gasparyan, Williams took a trip down memory lane with reporters during her press conference. They asked her about past victories over Sharapova.
She remembered the 2007 Australian Open in which she demolished Sharapova, 6-1, 6-2. "I remember I made up my mind I have absolutely nothing to lose in this match, and, I don't know, I just started playing really well...Because she was the favorite. She was No. 1. I really didn't have anything to lose, so it was just like, 'Hey, I'm just going to go for broke.'"
Now she's No. 1 and the favorite. Yet Williams tells herself and the press that she has nothing to lose.
But of course she does. The streak, another shot at tying Graf and rankings points are all something to lose. Likewise, Sharapova has her own legacy to consider.
No matter how these two try to characterize the matchup, when Williams and Sharapova clash, we watch.