After picking up titles in the Middle East, Karolina Pliskova and Elina Svitolina seem to have all the momentum as the tour heads to Indian Wells and Miami. But how do their performances stack up against the year’s other top performers?

In this edition of WTA Insider Heat Index, Senior Writer Courtney Nguyen weighs in on who’s hot and who’s not after a fortnight in Dubai and Doha.

For more on the Heat Index and the methodology behind it, click here.

1. Serena Williams (Rank: No.1; RTS: No.1; Previous HI: 1)
2017 record: 8-1
Titles: Australian Open (January)
Recent activity: None.
Key Stat: Did not lose a set in Melbourne.

Serena has not played an event since winning her record-setting 23rd major title at the Australian Open in January, but given her propensity for party crashing some public courts, I’m guessing she’s still healthy and in good spirits. That bodes well for the upcoming Sunshine Double swing through Indian Wells and Miami.

2. Karolina Pliskova (Rank: No.3; RTS: No.3; Previous HI: 2)
2017 record: 15-2
Titles: Brisbane International (January), Qatar Total Open (February)
Recent activity: Doha champion.
Key Stat: The first woman to win two titles this season.

The World No.3 has looked virtually unbeatable in 2017. When it comes to quality wins, no one has been better. Two months into the season and Pliskova already has wins over Dominika Cibulkova, Caroline Wozniacki, Garbiñe Muguruza, and Elina Svitolina.

3. Elina Svitolina (Rank: No.10; RTS: No.2; Previous HI: No.8)
2017 Record: 17-2
Titles: Taiwan Open (February), Dubai Duty Free Tennis Championships (February)
Recent activity: Taiwan Open champion, Dubai champion.
Key Stat: Currently on a 13-match winning streak since the Australian Open.

This is what we were waiting for. After tallying five career titles on the International level and improving her year-end ranking year over year, Svitolina put it all together in Dubai to win the biggest title of her career and make her Top 10 debut. With her third straight win over Angelique Kerber, she ended the German’s quest to retake the No.1 ranking and followed it up with a cool performance to beat Caroline Wozniacki in the final.

4. Caroline Wozniacki (Rank: No.14; RTS: No. 5; Previous HI: Unranked)
2017 record: 15-5.
Titles: None.
Recent activity: Runner-up in Doha and Dubai.
Key Stat: Wozniacki already has 15 wins this year. Her 15th match win last year came at the US Open in September.

Is Woz back? It sure does seem that way. The Dane made back-to-back finals in February in Doha (l. Pliskova) and Dubai (l. Svitolina) and she’s continued the fantastic run of form that’s kicked in since the start of the US Open last fall. In fact, if you isolate the ranking points earned since the start of the US Open, Wozniacki is at No.3 behind Kerber and Pliskova. Wozniacki has beaten just one Top 10 player so far this season, a win over Agnieszka Radwanska in Doha, but with less than 200 points to defend from no until the US Open, there’s no doubt a return to the Top 10 — Top 5? — is coming soon.

5. Johanna Konta (Rank: No.11; RTS: No.6; Previous HI: No.2)
2017 record: 15-3
Titles: Apia International Sydney (January)
Recent activity: Went 3-1 in Fed Cup (l. to Konjuh)
Key stat: Konta’s win over Radwanska in the Sydney final was her first over a Top 5 player in over a year.

Konta took her good form into Fed Cup and helped earn Great Britain a chance at promotion to the World Group. A foot injury prevented her from making her debut in the Middle East in Dubai, but with plenty of rest before the upcoming hard court swing, Konta should be in good form.

6. Angelique Kerber (Rank: No.2; RTS: No.9; Previous HI: No.6)
2017 record: 7-5
Titles: None
Recent activity: Dubai semifinalist.
Key stat: Kerber is 0-5 vs. Top 35 players.

After a disappointing January, Kerber showed signs of life in Dubai, playing cleaner, more aggressive tennis to make her first semifinal of the year. The quality was a step in the right direction. I still maintain it’s too early to write off the woman who won two hard court Slams last year. Now, if she continues to struggle through March…then it’s time to have the discussion.

7. Dominika Cibulkova (Rank: No.5; RTS: No.5; Previous HI: No.11)
2017 record: 8-6
Titles: None
Recent activity: Doha semifinalist.
Key stat: Made back-to-back semifinals in St. Petersburg and Doha.

The Middle East swing was a mixed bag for Cibulkova. She lost to eventual champion Pliskova in Doha, but in Dubai she was confounded once again by Ekaterina Makarova, who also beat her at the Australian Open. But much like Kerber, the level of tennis she played was an improvement on what we saw in January and she’s put in extra work with her mental coach to help her deal with the expectations of being a Top 5 player. She started to feel like herself again after Doha, and that’s good news for her tennis.

8. Agnieszka Radwanska (Rank: No.6; RTS: No.16; Previous HI: No.5)
2017 record: 7-5
Titles: None
Recent activity: Lost in Round of 16 in Doha (l. Wozniacki) and Dubai (l. Bellis)
Key stat: Has not won back-to-back matches in her last three events.

After solid outings in her first two tournaments of the year, the World No.6 has struggled to find her confidence and feel. Remember, this is a player who made the semifinals or better of her first four events last season. Her inability to solve 17-year-old CiCi Bellis in Dubai was a shocker. She’s frustrated and searching.

9. CoCo Vandeweghe (Rank: No.22; RTS: No.7; Previous HI: No.7)
2017 record: 8-3
Titles: None
Recent activity: Went 2-0 at Fed Cup; first round loss to Alison Riske in Dubai.
Key stat: Vandeweghe beat Kerber and Muguruza at the Australian Open. It was just the second time in her career she’s beaten two Top 10 players at a tournament (2014 Rogers Cup, Ivanovic and Jankovic).

The question for Vandeweghe after the Australian Open wasn’t whether she had Slam-winning tennis inside her — the quality during the Melbourne fortnight was top-notch — but whether she could maintain a consistent level. Indian Wells and Miami should serve as better litmus tests.

10. Kristina Mladenovic (Rank: No.30; RTS: No.14; Previous HI: Unranked)
2017 record: 8-4
Titles: St. Petersburg
Recent activity: Beat Pliskova in Dubai, semifinalist in Acapulco (tournament ongoing).
Key stat: Her win over Pliskova was her first Top 5 win since 2015.

Mladenovic will be the first to tell you her tennis can reach the highest of highs and, at times, head-scratching lows, but it makes her game all the more compelling. After winning her first title in St. Petersburg, Mladenovic scored a big win over Pliskova only to lose to No.76 Wang Qiang in straight sets the next day. Regardless, she’s been consistently dangerous early this season.

11. Garbiñe Muguruza (Rank: No.7; RTS: No.10; Previous HI: No.4)
2017 record: 9-5
Titles: None
Recent activity: Went 1-2 during Middle East swing.
Key stat: Two of her four tournaments this season has ended in a retirement.

The primary reason surrounding Muguruza’s notable drop in the Heat Index is injury related. She picked up a left Achilles injury in Doha, which forced her to retire from a match in Dubai for the second time this season. In January she retired from the Brisbane semifinals due to an abductor injury. It’s a disconcerting trend for the Spaniard, just two months into the season.

12. Venus Williams (Rank: No.13; RTS: No.4; Previous HI: No.10)
2017 record: 7-2
Titles: None
Recent activity: None
Key stat: This time last year, Venus was also 7-2. She lost in the first round of Auckland and the Australian Open before winning seven straight matches at Fed Cup and en route to the Taiwan Open title.

With the surges from Wozniacki and Mladenovic into this edition of the Heat Index, Venus drops two spots. She did not play a tournament in February, so I’m looking forward to seeing how she’s feeling in Indian Wells next week. If it’s anything like what we saw in Melbourne, it will be a treat.