Who are the 10 best clay-court players heading into Roland Garros? WTA Insider crunches the numbers.
WTA Insider Courtney Nguyen
May 23, 2018

PARIS, France - With Roland Garros just around the corner, World No.1 Simona Halep and clay-court stalwart Kiki Bertens top the WTA Insider Clay Court Power Rankings heading into Paris, while Madrid champion Petra Kvitova and Stuttgart champion Karolina Pliskova make their respective debuts on the Top 10 list.

A champion in Charleston and runner-up in Madrid, No.18 Bertens has posted an 11-3 record on clay this season, a record bested only by Kvitova, who comes to Paris riding an 11-match win-streak after back-to-back titles in Prague and Madrid. A surprise semifinalist in Paris last year, Pliskova's confidence on clay continued to rise this season after winning her biggest title on clay in Stuttgart and consolidating that win with a run to the Madrid semifinals. 

2017 Roland Garros champion Jelena Ostapenko and her mother pose with the Coupe Suzanne Lenglen

The WTA Insider Clay Court Power Rankings are based on an empirical formula that isolates a player's success rate on clay 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 clay courts in 2018
100% of points earned on clay courts in 2017
75% of points earned on clay courts in 2016
50% of points earned on clay courts in 2015

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

As a refresher, here's a summary of who has dominated the tour's biggest clay-court titles over that four-year span:

Roland Garros: Jelena Ostapenko (2017), Garbiñe Muguruza (2016), Serena Williams (2015).
Mutua Madrid Open: Petra Kvitova (2018), Simona Halep (2017, 2016), Petra Kvitova (2015).
Internazionali BNL d'Italia: Elina Svitolina (2018), Elina Svitolina (2017), Serena Williams (2016), Maria Sharapova (2015).
Porsche Tennis Grand Prix: Karolina Pliskova (2018), Laura Siegemund (2017), Angelique Kerber (2016, 2015)
Volvo Car Open: Kiki Bertens (2018), Daria Kasatkina (2017), Sloane Stephens (2016), Angelique Kerber (2015).

A more detailed breakdown of the WTA Insider Clay Court Power Rankings Top 10 follows below. Match records do not include this week's results in Nuremberg and Strasbourg. 

Here are the Top 10 on the WTA Insider Clay Court Power Rankings heading into Roland Garros. 

No.1 Simona Halep (WTA Rank: No.1)
Career Clay Court Win %: .708
2018 Clay Court Record: 9-3 (l. Vandeweghe, Pliskova, Svitolina)
Notable recent clay court results: 2018 Rome finalist, 2018 Madrid semifinalist, 2017 Roland Garros finalist, 2017 and 2016 Madrid champion, 2017 Rome finalist, 2016 Roland Garros Round of 16, 2015 Rome semifinalist, 2015 Stuttgart semifinalist.

No.2 Kiki Bertens (WTA Rank: No.18)
Career Clay Court Win %:
.694
2018 Clay Court Record: 11-3* (l. Pliskova, Kvitova, Sakkari)
Notable recent clay court results: 2018 Madrid finalist, 2018 Charleston champion, 2017 Gstaad champion, 2017 and 2016 Nuremberg champion, 2016 Gstaad finalist.

No.3 Elina Svitolina (WTA Rank: No.4)
Career Clay Court Win %:
.646
2018 Clay Court Record: 7-2 (l. Garcia, Suárez Navarro)
Notable recent clay court results: 2018 and 2017 Rome champion, 2017 Roland Garros quarterfinalist, 2017 Istanbul champion, 2016 Roland Garros Round of 16, 2015 Roland Garros quarterfinalist, 2015 Marrakech champion. 

No.4 Jelena Ostapenko (WTA Rank: No.5)
Career Clay Court Win %:
.656
2018 Clay Court Record: 6-3 (l. Pliskova, Begu, Sharapova)
Notable recent clay court results: Reigning Roland Garros champion, 2018 Rome quarterfinals, 2018 Stuttgart quarterfinals, 2017 Charleston finalist, 2017 Prague semifinalist. 

No.5 Serena Williams (WTA Rank: No.453; Protected Ranking: No.1)
Career Clay Court Win %:
.831
2018 Clay Court Record: DNP
Notable recent clay court results: 2015 Roland Garros champion, 2016 Roland Garros finalist, 2016 Rome champion. Did not play on clay in 2017. 

No.6 Garbiñe Muguruza (WTA Rank: No.3)
Career Clay Court Win %:
.632
2018 Clay Court Record: 4-3 (l. Pavlyuchenkova, Kasatkina, Gavrilova)
Notable recent clay court results: 2016 Roland Garros champion, 2017 and 2016 Rome semifinalist, 2017 Roland Garros Round of 16, 2015 Roland Garros quarterfinalist.

No.7 Samantha Stosur (WTA Rank: No.60)
Career Clay Court Win %:
.657
2018 Clay Court Record: 3-4* (l. Ahn, Giorgi, Stephens, Van Uytvanck)
Notable recent clay court results: 2017 Strasbourg champion, 2016 Roland Garros semifinalist, 2016 Prague finalist, 2016 Madrid semifinalist, 2015 Strasbourg champion, 2015 Bad Gastein champion. 

No.8. Karolina Pliskova (WTA Rank: No.6)
Career Clay Court Win %:
.573
2018 Clay Court Record: 10-3 (l. Goerges, Kvitova, Sakkari)
Notable recent clay court results: 2018 Stuttgart champion, 2018 Madrid semifinalist, 2017 Roland Garros semifinalist, 2017 Rome quarterfinalist, 2017 Stuttgart quarterfinalist, 2016 Prague semifinalist, 2016 Stuttgart quarterfinalist, 2015 Prague champion. 

No.9 Petra Kvitova (WTA Rank: No.8)
Career Clay Court Win %: .664
2018 Clay Court Record: 13-2 (l. Kr. Pliskova, Kerber)
Notable recent clay court results: 2018 Madrid champion, 2018 Prague champion, 2016 Stuttgart semifinalist, 2015 Roland Garros Round of 16, 2015 Rome quarterfinalist, 2015 Madrid champion.

No.10 Timea Bacsinszky (WTA Rank: 63)
Career Clay Court Win %:
.602
2018 Clay Court Record: 0-1 (l. Begu)
Notable recent clay court results: 2017 and 2015 Roland Garros semifinalist, 2016 Roland Garros quarterfinalist, 2016 Rome quarterfinalist, 2016 Rabat champion, 2016 Gstaad semifinalist.

*Entered in this week's events in Nuremberg or Strasbourg.