The first WTA 1000 event of the clay season is here, with the 12th edition of the Mutua Madrid Open set to kick off on Thursday. WTA Insider breaks down the key storylines from this year's unique 10-day event.

1. The Mutua Madrid Open is the first WTA 1000 of the clay season

The clay season saw two WTA 500 events at the Volvo Car Open and last week's Porsche Tennis Grand Prix. Now the stakes are heightened. The Mutua Madrid Open and Internazionali BNL d'Italia offer back-to-back WTA 1000 events ahead of Roland Garros, which begins on May 24th.

The Madrid Open features a 64-player singles draw and a 30-team doubles draw. The winner will earn 1,000 ranking points and the runner-up will win 650 points. 

2. This year the Madrid Open is a 10-day event

Main draw play begins on Thursday, April 29, and both singles and doubles finals will be played on Saturday, May 8. The Round of 16 will be split across Monday and Tuesday, with quarterfinals being played Wednesday and semifinals on Thursday. 

3. World No.1 Ashleigh Barty leads the draw, Naomi Osaka returns

The main draw features 17 of the Top 20, with World No.1 Barty leading the draw with World No.2 Naomi Osaka. Barty comes into Madrid fresh off her tour-leading third title in Stuttgart, having overtaken Osaka at No.1 on the Porsche Race to Shenzhen Leaderboard. Osaka is playing her first tournament since the Miami Open, and the first clay event since 2019 Roland Garros. Click here for the full draw. 

Top Eight Seeds: 1. Ashleigh Barty, 2. Naomi Osaka, 3. Simona Halep, 4. Elina Svitolina, 5. Aryna Sabalenka, 6. Karolina Pliskova, 7. Kiki Bertens, 8. Belinda Bencic. 

Wildcards: Paula Badosa, Sorana Cirstea, Victoria Jimenez Kasinteva, Sara Sorribes Tormo and Venus Williams.

4. The Main Draw is a blockbuster from the get-go

Top Half Potential Round of 16: [1] Ashleigh Barty vs. [14] Iga Swiatek, [9] Petra Kvitova vs. [7] Kiki Bertens, [4] Elina Svitolina vs. [15] Johanna Konta, [10] Garbiñe Muguruza vs. [8] Belinda Bencic.

Bottom Half Potential Round of 16: [5] Aryna Sabalenka vs. [12] Victoria Azarenka, [13] Elise Mertens vs. [3] Simona Halep, [6] Karolina Pliskova vs. [11] Jennifer Brady, [16] Maria Sakkari vs. [2] Naomi Osaka.

For a full breakdown of the main draw, click here

5. Popcorn first-round matches.

The top half of the draw will play Thursday and Saturday, while the bottom half will play on Friday and Sunday. 

Notable first-round matches - Top Half
Ashleigh Barty vs. Shelby Rogers
Petra Kvitova vs. Marie Bouzkova
Angelique Kerber vs. Marketa Voundrousova
Paula Badosa vs. Barbora Krejcikova
Johanna Konta vs. Yulia Putintseva
Garbiñe Muguruza vs. Sloane Stephens

Notable first-round matches - Bottom Half
Jessica Pegula vs. Sorana Cirstea
Simona Halep vs. Sara Sorribes Tormo
Karolina Pliskova vs. Coco Gauff
Anastasia Pavlyuchenkova vs. Madison Keys
Svetlana Kuznetsova vs. Jelena Ostapenko
Jennifer Brady vs. Venus Williams
Maria Sakkari vs. Amanda Anisimova

6. Clay Court Power Rankings: How the field stacks up on clay

For more on the methodology behind the WTA Insider Clay Court Power Rankings, click here

7. Madrid has served as a transformative springboard

There's something about the Caja Magica that instills belief and confidence in players. The conditions in Madrid are unique and require meaningful adjustment, but the combination of altitude, balls and clay have rewarded both pure ball-strikers as well as the game's best clay-courters. The three former champions in the draw, Simona Halep, Petra Kvitova, and Kiki Bertens, count Madrid as a seminal event in their careers.

"It was my first tournament when I really realized I can play well on the clay," three-time champion Kvitova told reporters at Media Day. "I think it was 2011 when it was my season when I won Wimby and WTA Finals. Of course, I won some tournaments even before, but Madrid was the biggest I won that year.

"I think it really showed me that I can play well not even on the clay but I can beat the best players in the world. I think it really gave me a lot of experiences as well and confidence at times."

2019 Roland Garros champion Barty once said that every day of clay season was a day closer to the grass season, but the World No.1 cites her match against Simona Halep at the 2019 Madrid Open, a 7-5, 7-5 loss in the quarterfinals, as a turning point for her understanding of how her game could excel on the surface.

"I think the match against Simo in Madrid that year was a little bit of a game-changer in a sense," Barty told WTA Insider after winning Miami. "I just felt like I learned a lot in that match from the best clay courter in the world, in my opinion. There was not a lot in it. The couple of times that I got broken, I just pressed. To lose five and five, certainly no shame in that."

For Halep and Bertens, the two purest clay-courters in the game, something about Madrid just clicks with their game. 

"Once I step out here, it feels good," defending champion Bertens said. "I think the altitude is helping me a little bit. The balls are great. Of course, the courts, I really love them. Especially when you play on the center court or the other two courts, it's kind of indoors.

"For me, it's like the perfect circumstances to play tennis. When it goes automatically with me, I think I play my best tennis. That's how I feel here."

8. Naomi Osaka gets her clay season underway

After a brief respite to spend time with family and recharge, the reigning Australian Open champion gets her 2021 clay season started this week in Madrid. She will face a qualifier in the first round Friday, with the winner to face either Australian Open semifinalist Karolina Muchova or China's Wang Qiang. A rematch with Maria Sakkari, who ended her 23-match winning streak in the Miami quarterfinals, could happen in the Round of 16 and an Australian Open final rematch against Jennifer Brady could be in the cards for the quarterfinals. 

READ: As hard-court streak ends, Osaka embraces clay challenge

9. Spaniards hope to bring season success into Madrid

It has been a banner season for the Spaniards on the WTA Tour and the standout trio of Garbiñe Muguruza, Sara Sorrbes Tormo, and Paula Badosa will be looking to celebrate it on home soil. 

Seeded No.10, Muguruza brings her tour-leading 21-6 record to the Caja Magica, where she is looking to get past the Round of 16 for the first time. Coming off a leg injury that forced her to retire in Charleston, Muguruza will face 2019 semifinalist Sloane Stephens in the first round, with Ons Jabeur and Belinda Bencic as potential opponents before the quarterfinals. Drawn into the top half, Muguruza could face No.1 Barty in the semifinals.

Guadalajara champion Sorribes Tormo faces the tough task of opening against two-time champion Simona Halep. The two faced-off for the first time last year at Roland Garros and the Spaniard won four games. An upset would continue to cement her as a player no one wants to face on any surface

No.62 Badosa is into the main draw with a wildcard and will face Dubai finalist Barbora Krejcikova in the first round. The young Spaniard is the midst of the best season of her career, having made the semifinals in Lyon and Charleston.

10. Hsieh Su-Wei and Elise Mertens team up to lead the doubles draw

With Barbora Strycova on maternity leave and Aryna Sabalenka making good on her decision to focus her efforts on singles, Hsieh Su-Wei and Elise Mertens are set to play their first event together in Madrid. As the rankings would have it, pending results, Mertens is in a strong position to overtake Hsieh atop the WTA Doubles Rankings after Madrid. 

Champion's Reel: How Kiki Bertens made history with 2019 Madrid title run

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