MELBOURNE, Australia - The 2019 WTA season is in full swing as the tour heads towards the first major of the season at the Australian Open, which begins on Monday, January 14th. As the tour is set to jump from Australia to the Middle East and back to the United States, it's time to check in on WTA Insider Hard Court Power Rankings to isolate the players who have a recent track record of flourishing on hard courts. 

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."

Note that the Power Index formula has been adjusted in 2019. In previous years, 100% of the points earned from the current season and previous season were taken into account. In order to provide a more accurate reflection of recent form, the revised formula takes 100% of the points from the current season and 75% of the previous season.

As a refresher, here's who dominated the Australian swing in 2018:

Australian Open: Caroline Wozniacki d. Simona Halep
Sydney International: Angelique Kerber d. Ashleigh Barty
Brisbane International: Elina Svitolina d. Aliaksandra Sasnovich
Shenzhen Open: Simona Halep d. Katerina Siniakova
ASB Classic: Julia Goerges d. Caroline Wozniacki
Hobart International: Elise Mertens d. Mihaela Buzarnescu

Here are the Top 20 on the WTA Insider Hard Court Power Rankings heading into the 2019 Australian Open. Note that this week's results at the Sydney International and Hobart International have not been included. 

No.1 Caroline Wozniacki  (WTA Rank: No.3)
2018 Hard Court Record:
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, 

No.2 Karolina Pliskova (WTA Rank: No.7)
2018 Hard Court Record: 
Recent Hard Court Results: 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.

READ: Karolina Pliskova soaking up the Aussie summer - 'I love this place so much'

No.3 Elina Svitolina (WTA Rank: No.6)
2018 Hard Court Record:
Recent Hard Court Results: 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. 

READ: Champions Corner - Elina Svitolina stuns in Singapore

No.4 Simona Halep (WTA Rank: No.1)
2018 Hard Court Record:
Notable Hard Court Results: 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.

READ: Simona Halep set to fly solo in 'chill' start to season

No.5 Angelique Kerber (WTA Rank: No.2)
2018 Hard Court Record:
Recent Hard Court Results: 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.

No.6 Naomi Osaka (WTA Rank: No.4)
2018 Hard Court Record:
Recent Hard Court Results: 2019 Brisbane semifinalist, 2018 China Open semifinalist, 2018 Tokyo finalist, 2018 US Open champion, 2018 Indian Wells champion, 2016 Tokyo finalist.

No.7 Sloane Stephens (WTA Rank: No.5)
2018 Hard Court Record:
Recent 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. 

No.8 Garbiñe Muguruza (WTA Rank: No.18)
2018 Hard Court Record:
Recent Hard Court Results: 2018 Monterrey champion, 2018 Dubai semifinalist, 2018 Doha finalist, 2017 Cincinnati champion, 2017 Australian Open quarterfinalist, 2016 Cincinnati semifinalist.

No.9 Petra Kvitova (WTA Rank: No.8)
2018 Hard Court Record:
Recent Hard Court Results: Cincinnati semifinalist, Doha champion, St. Petersburg champion, 2017 Beijing semifinalist, 2017 US Open quarterfinalist, 2016 Zhuhai champion, 2016 Luxembourg finalist, 2016 Wuhan champion.

No.10 Caroline Garcia (WTA Rank: No.19)
2018 Hard Court Record:
Recent Hard Court Results:2018 Tianjin Open champion, 2017 WTA Finals semifinalist, 2017 Beijing champion, 2017 Wuhan champion.

Here's who rounds out the Top 20:

No.11 Julia Goerges: 3006.25
No.12 Venus Williams: 2982.75
No.13 Madison Keys: 2975.25
No.14 Anastasija Sevastova: 2876.50
No.15 Serena Williams: 2804.50
No.16 Johanna Konta: 2766.75
No.17 Aryna Sabalenka: 2630.75
No.18 Ashleigh Barty: 2598.00
No.19 Daria Kasatkina: 2586.00
No.20 Dominika Cibulkova: 2529.00