At the Net: An early WTA report card

Philadelphia, PA – How have the top women fared on the WTA this year?

Let's take a look.

(1) SERENA WILLIAMS

The veteran star has been slowed by back and ankle injuries in recent weeks, but is still 12-2 and has appeared in two finals (1-1) in three events. The reigning Wimbledon and U.S. Open champion titled in Brisbane, Australia, to open her year and lost to her latest main rival Victoria Azarenka in a final in Doha, Qatar, a few weeks ago. Williams was stunned by rising star and fellow American Sloane Stephens in last month's Australian Open quarterfinals, but the 31-year-old still recently replaced Azarenka atop the WTA rankings to become the oldest-ever world No. 1.

Grade: B+

(2) VICTORIA AZARENKA

The Belarusian star has yet to lose this season, going 14-0, including a second straight Aussie Open title and the win in Qatar. In her first tourney of the year in Brisbane, the former No. 1 pulled out of a scheduled semifinal match with Williams, citing "whatever." Actually, it was an infected big toe, which came as the result of a "bad pedicure." The 2012 U.S. Open runner-up to Serena is already 4-0 against her fellow top-10ers this season and heads to the big BNP Paribas Open in Indian Wells, Calif., seeking a third title in four events.

Grade: A

(3) MARIA SHARAPOVA

The tall Russian bomber has yet to appear in a final this year, but she's only played in two events. The French Open champ and former world No. 1, "Shaza" lost to Li Na in the Aussie Open semis and to Serena in the final four in Doha last month. She's been fairly inactive at best.

Grade: B-

(4) AGNIESZKA RADWANSKA

Last year's Wimbledon runner-up to Serena got off to a wicked-hot start in 2013, nailing down back-to-back titles at Aussie Open tune-ups in Auckland and Sydney before suffering a mild-upset loss at the hands of the aforementioned Li in the quarters in Oz. The active Pole is a quality 17-3, but failed to get past the semis in her last three events. She succumbed to Azarenka in a semi in Doha and gave way to former Wimbledon champ Petra Kvitova in a quarterfinal in Dubai two weeks ago.

Grade: A-

(5) LI NA

The Chinese star landed in her second Aussie Open final in three years (losing for a second time) and reached a final in her native China to open the year, which she did by titling in Shenzhen in January. The 31-year-old former French Open champ is 14-2, including a semifinal loss against Radwanska in a semifinal in Sydney, and has not played a WTA match since losing to Azarenka in the Aussie finale over a month ago. She'll be on hand for the star-studded Indian Wells event, her fourth tourney of the year.

Grade: A+

(6) ANGELIQUE KERBER

The German southpaw is off to a slow start this year, coming off her breakthrough campaign that was 2012. The world No. 6 hasn't reached a quarterfinal in her last three events, including second-round losses against fellow German Mona Barthel in Doha and Italian Roberta Vinci in Dubai. Angie was also a disappointing fourth-round loser against average Russian Ekaterina Makarova at the Aussie, this after reaching the quarters in Brisbane and semis in Sydney. She's settled for a 7-5 record to date, including setbacks in her last three outings.

Grade: D-

(7) PETRA KVITOVA

The big Czech lefty got off to a brutal start this season, going 3-4 over her first four events, including a second-round upset at the hands of promising British southpaw Laura Robson at the Aussie. But she's certainly picked up the pace since then. PK posted a pair of Fed Cup singles wins against Australia, reached a quarterfinal in Doha (only to lose to the formidable Serena), and then notched a big title in Dubai with a victory over Roland Garros runner-up Sara Errani in the final. All told, she's 12-5 for the year.

Grade: C+

(8) SARA ERRANI

The Italian grinder has been the most-active top-10 woman, appearing in no less than eight events, and posting a 19-8 record. And she's been hot the last few weeks, reaching the final in Dubai (a loss to Kvitova) and capturing a title in Acapulco, Mexico, last week. The Bologna native also reached a final in Paris last month, but lost to the aforementioned rising Barthel in that one.

Grade: B+

(9) SAMANTHA STOSUR

Of course, Stosur went belly-up at her home Slam in January, bowing out at the Aussie Open in only the second round. She's been a first- or second-round loser in Melbourne six times in 11 trips there. But she's just simply been losing everywhere this year, posting a measly 5-7 record and only two quarterfinal appearances in five tournaments. She got off to a dismal 1-5 start in 2013 before securing a quarterfinal berth in Doha.

Grade: F

(10) CAROLINE WOZNIACKI

The former No. 1 has yet to reach a final in six events. She was an opening- round loser in Malaysia last week after reaching a semifinal in Dubai the week before (a loss to Kvitova). The delightful Dane was a disappointing fourth- round loser at the Aussie and is just 10-6 this season, including tournament-opening losses at two events.

Grade: C-

The tour is in Indian Wells for the next two weeks, as the stop in the California desert serves as a Premier Mandatory event on the women's circuit, unless you are Serena, who had a falling out with the tourney several years ago and has vowed to never play there again.

It's looking like she won't.