WTA Insider crunches the numbers to highlight the ones to watch as the North American summer hardcourt season begins.
WTA Insider Courtney Nguyen
July 25, 2019

The North American summer hardcourt swing begins next week at the Mubadala Silicon Valley Classic and Citi Open, which means it's time to dust off the WTA Insider Hard Court Power Rankings. 

World No.3 Karolina Pliskova, who leads the tour hard-court wins this season, tops the WTA Insider Hard Court Power Rankings, while Miami Open champion and the winningest player across all surfaces, World No.1 Ashleigh Barty, makes her Hard Court Power Rankings debut at No.10.

Wimbledon champion Simona Halep, ranked No.6 on the Power Rankings, is soaring in confidence as she returns to a section of the season in which she's always performed well. And reigning US Open champion and World No.2 Naomi Osaka returns to her favorite surface and readies for her first major title defense. Her incredible 17 months puts her at No.4 on the Power Rankings.

READ: Where are the Top 20 playing this summer? 

The WTA Insider Hard Court Power Rankings are based on an empirical formula that isolates a player's success rate on hard courts. To measure a player's recent aptitude on the surface, the Insider team applied the following formula, which takes into account a player's results over the last four seasons:

100% of points earned on hard courts in 2019
75% of points earned on hard courts in 2018
50% of points earned on hard courts in 2017
25% of points earned on hard courts in 2016

The resulting sum accounts for a player's "Hard Court Index."

As a refresher, here's who dominated the North American summer last year

US Open: Naomi Osaka d. Serena Williams
Montreal (Premier 5): Simona Halep d. Sloane Stephens
Cincinnati (Premier 5): Kiki Bertens d. Simona Halep

New Haven (Premier): Aryna Sabalenka d. Carla Suárez Navarro
San Jose (Premier): Mihaela Buzarnescu d. Maria Sakkari
Washinton D.C. (International): Svetlana Kuznetsova d. Donna Vekic

With the summer hard court season set to begin, here are the Top 10 on the WTA Insider Hard Court Power Rankings:

1. Karolina Pliskova (WTA Rank: No.3; PRTS: No.3)
2019 Hard Court Record:
21-5 (80.8%)
Career Hard Court Win Percentage: 67.2%
Notable Hard Court Results: 2019 Australian Open semifinalist, 2019 Miami finalist, 2019 & 2016 Brisbane International champion, 2018 & 2017 WTA Finals semifinalist, 2018 Tianjin Open champion, 2018 Toray Pan Pacific Open champion, 2018 US Open quarterfinalist, 2018 Australian Open quarterfinalist, 2017 US Open quarterfinalist, 2017 Cincinnati semifinalist, 2017 Miami semifinalist, 2017 Indian Wells semifinalist, 2017 Doha champion, 2017 Australian Open quarterfinalist, 2017 Brisbane champion, 2016 US Open finalist, 2016 Cincinnati champion, 2016 Indian Wells semifinalist.

2. Elina Svitolina (WTA Rank: No.7; PRTS: No.10)
2019 Hard Court Record:
13-6 (68.4%)
Career Hard Court Win Percentage: 66.8%
Notable Hard Court Results: 2019 Indian Wells semifinalist, 2018 WTA Finals champion, 2018 Montreal semifinalist, 2018 & 2017 Dubai champion, 2018 Australian Open quarterfinalist, 2018 Brisbane champion, 2017 Toronto champion, 2017 Taipei champion, 2016 Beijing semifinalist, 2016 New Haven finalist, 2016 Kuala Lumpur champion. 

3. Caroline Wozniacki (WTA Rank: No.18; PRTS: No.50)
2019 Hard Court Record:
5-4 (55.6%)
Career Hard Court Win Percentage: 73.0%
Notable Hard Court Results: 2018 China Open champion, 2018 Doha semifinalist, 2018 Australian Open champion, 2018 Auckland finalist, 2017 WTA Finals champion, 2017 Tokyo champion, 2017 Toronto finalist, 2017 Miami finalist, 2017 Dubai finalist, 2017 Doha finalist, 2016 Hong Kong champion, 2016 Tokyo champion, 2016 US Open semifinalist.

4. Naomi Osaka (WTA Rank: No.2; PRTS: No.6)
2019 Hard Court Record:
12-4 (75.0%)
Career Hard Court Win Percentage: 62.6%
Notable Hard Court Results: 2019 Australian Open champion, 2019 Brisbane semifinalist, 2018 China Open semifinalist, 2018 Tokyo finalist, 2018 US Open champion, 2018 Indian Wells champion, 2016 Tokyo finalist.

5. Angelique Kerber (WTA Rank: No.13; PRTS: No.11)
2019 Hard Court Record:
16-7 (69.6%)
Career Hard Court Win Percentage: 66.4%
Notable Hard Court Results: 2019 Indian Wells finalist, 2018 Australian Open semifinalist, 2018 Sydney champion, 2017 Monterrey finalist, 2017 Dubai semifinalist, 2016 WTA Finals finalist, 2016 US Open champion, 2016 Cincinnati finalist, 2016 Montreal semifinalist, 2016 Miami semifinalist, 2016 Australian Open champion, 2016 Brisbane finalist.

6. Simona Halep (WTA Rank: No.4; PRTS: No.2)
2019 Hard Court Record:
16-6 (72.7%)
Career Hard Court Win Percentage: 67.2%
Notable Hard Court Results: 2019 Doha finalist, 2019 Miami semifinalist, 2018 Cincinnati finalist, 2018 Montreal champion, 2018 Indian Wells semifinalist, 2018 Doha semifinalist, 2018 Australian Open finalist, 2018 Shenzhen champion, 2017 China Open finalist, 2017 Cincinnati finalist, 2017 Toronto semifinalist, 2016 Wuhan semifinalist, 2016 US Open quarterfinalist, 2016 Cincinnati semifinalist, 2016 Montreal champion.

7. Petra Kvitova (WTA Rank: No.6; PRTS: No.4)
2019 Hard Court Record:
20-6 (76.9%)
Career Hard Court Win Percentage: 69.0%
Notable Hard Court Results: 2019 Dubai finalist, 2019 Australian Open finalist, 2019 Sydney champion, 2018 Cincinnati semifinalist, 2018 Doha champion, 2018 St. Petersburg champion, 2017 Beijing semifinalist, 2017 US Open quarterfinalist, 2016 Zhuhai champion, 2016 Luxembourg finalist, 2016 Wuhan champion.

8. Garbiñe Muguruza (WTA Rank: No.27; PRTS: No.24)
2019 Hard Court Record:
16-7 (69.6%)
Career Hard Court Win Percentage: 63.9%
Notable Hard Court Results: 2019 and 2018 Monterrey champion, 2018 Dubai semifinalist, 2018 Doha finalist, 2017 Cincinnati champion, 2017 Australian Open quarterfinalist, 2016 Cincinnati semifinalist.

9. Sloane Stephens (WTA Rank: No.8; PRTS: No.16)
2019 Hard Court Record:
6-6 (50.0%)
Career Hard Court Win Percentage: 59.8%
Notable Hard Court Results: 2018 WTA Finals finalist, 2018 US Open quarterfinalist, 2018 Montreal finalist, 2018 Miami Open champion, 2017 US Open champion, 2016 Acapulco champion, 2016 Auckland champion. 

10. Ashleigh Barty (WTA Rank: No.1; PRTS: No.1)
2019 Hard Court Record:
20-3 (87.0%)
Career Hard Court Win Percentage: 68.9%
Notable Hard Court Results: 2019 Miami champion, 2019 Australian Open quarterfinalist, 2019 Sydney finalist, 2018 Zhuhai champion, 2018 Wuhan semifinalist, 2018 Montreal semifinalist, 2018 Sydney final, 2017 Wuhan final, 2017 Kuala Lumpur champion.