So far, so good for Maria Sharapova

Men's first-quarter report | Women's first-quarter report

How have the women fared through the first quarter of the season?

1. Serena Williams: Slight gain

Getting injured at the Australian Open will be the dominating disappointment of this quarter for Serena Williams. There were some positives, however: She returned to No. 1 for the first time since 2010 and won a sixth title in Miami.

She remains "the boss" of the tour (as coach Patrick Mouratoglou put it following the Miami win), but rivals Victoria Azarenka and Maria Sharapova did make some inroads into their otherwise one-sided head-to-heads. Azarenka defeated Williams in Doha, while Sharapova took her to three sets in Miami. For Williams though, a bigger concern might be the repeated physical problems she's had this season -- apart from the ankle and back problems at the Australian, she had to pull out of Dubai and may have been troubled by a hip issue in Miami.

2. Maria Sharapova: Gain

Not winning the Australian will also be Sharapova's main frustration of the season so far. She got off to a sizzling start but then fizzled against Li Na in the semifinals. But winning Indian Wells and reaching the final in Miami back-to-back was an impressive rebound, and it looks like she's playing the best she has since her comeback from surgery, even including her French Open win last year.

Beating Williams remains the stumbling block, and she has struggled frequently against Azarenka as well. But she is now firmly in the mix with them at the top of the game.

3. Victoria Azarenka: Unchanged

She did win the Australian Open, itself enough to make the quarter a success. Defeating Williams in the Doha final after a string of previous losses was also a notable achievement.

Even that's not quite as good as last year, when she won everything in sight until Miami, but she's also facing tougher opposition at the top and has struggled with injuries. Nearly all of her tournaments have featured some sort of problem -- she pulled out of the Brisbane semifinal against Williams over a pedicure mishap, then there were the controversial medical timeouts in the Australian Open semifinal, withdrawal from Dubai, pulling out of the Indian Wells semis against Caroline Wozniacki and withdrawing from Miami.

It's meant she's dropped from No. 1 to No. 3, but she's still made the most significant statements of the year so far.

4. Agnieszka Radwanska: Loss

She won two tournaments to start the year -- which would be a good thing except that they were right before the Australian Open, and she lost in the quarterfinals there. Her scheduling has been better since, with just four more tournaments. But Radwanska also doesn't look as strong as she did during the same period last year. She's again experiencing problems getting past the big power hitters, and her defense of the Miami title was comprehensively stopped by Serena Williams in the semifinals.

5. Li Na: Gain

The ankle injury she picked up in the Australian Open final kept her off the tour until Miami, so there aren't many results to look at. But her performances before and in Australia alone were enough to make her quarter a success.

6. Angelique Kerber: Loss

A player who surprised with her consistently high-quality results last year, Kerber seems to have dipped slightly. She's had quite a few early losses, and her moonball contest with Caroline Wozniacki at Indian Wells suggests her confidence isn't that high at the moment. But a lull isn't something to get too worried about, because she has come a long way in the last year and a half.

7. Sara Errani: Unchanged

After also doing surprisingly well last year, the question was whether Errani would be able to keep it up. Her wobbles at the start of the year raised doubts, but she's come back nicely with finals in Paris and Dubai and a title in Acapulco. Now comes her best surface, clay, but she's also got bigger results to defend.

8. Petra Kvitova: Unchanged

Kvitova had developed a habit of struggling during this part of the season, so a title in Dubai and decent results elsewhere are an acceptable showing. But she's capable of more.

9. Samantha Stosur: Loss

It's been tough so far. After starting the season with injury and her usual Aussie-time nervousness, Stosur had just got going when she had to pull out of her quarterfinal at Indian Wells and then miss Miami.

10. Caroline Wozniacki: Slight gain

After sliding steadily for most of last year, Wozniacki seems to have stopped the bleeding by reaching the Indian Wells final and posting some solid results at other tournaments. But she has also been complaining about the lack of consistency in her game, which is what she was known for during her No. 1 days. And she hasn't replaced that consistency with a lot more aggression, either. So there's still some way to go.

Other notables

Backed by compatriot and friend Kim Clijsters, Kirsten Flipkens is rising quickly. She reached the fourth round of the Australian Open and the quarterfinals of Miami, defeating Kvitova. Sloane Stephens is up to No. 16 but seems to be struggling to adjust to her rising profile since making her Australian Open semifinal. Svetlana Kuznetsova announced she was back in the mix by getting to the quarterfinals of Sydney as a qualifier and then the Australian Open quarterfinals, but since then she hasn't made any more big statements.

Men's first-quarter report | Women's first-quarter report