Most of the top women don't count clay as their preferred surface, and in the past few years, the big events have been won by power players who have games that aren't traditionally suited to the surface. With no dominant figure on the WTA this season and many of the usual clay-court players not playing well, there's potential for a lot of different names to emerge. Here are a few of the women to watch:
After going undefeated on her worst surface last year, Williams is winless so far this season, dropping her opener at Charleston. And she has been less than dominant recently, taking unexpected losses at the Australian Open and Dubai and saying she is feeling the effects of her heavy schedule during the past two years. All that suggests that while the world No. 1 begins as the favorite again, she may be more vulnerable, particularly as clay still does not play to her strengths.
But then again, who is there to take advantage? Few of the other top women like playing on clay, and the 32-year-old Williams now has more experience on it than most of her competition. The only players who managed to trouble her last year used classic clay tactics like spin and defense, such as Svetlana Kuznetsova at the French Open. But not many can play that game, and those who can have generally not been having good seasons.
2. Li Na
The 2011 French Open champ surprised even herself when she won her first Grand Slam on the clay, having thought the surface did not suit her power game. Since then, she had been having solid results on it -- until skidding at the three big clay events last year. But given her impressive play since then, she should be able to return to better things once again. Whether she'll be able to keep up any regular serve-and-volley attempts on the surface, however, is another question.
The 2012 French Open champ was another unexpected conqueror on clay but has improved on the surface over the years and benefits from the lack of clay specialists in the field. She has also been a consistent performer during this portion of the season during the past few years, regularly reaching the semifinals and finals. But her shoulder began giving her problems during these events a year ago, and Sharapova admitted at Miami that it is still not at full strength, so she could be affected during long matches.
The Russian is a great competitor, though, and she should continue to manage some decent results if she can avoid playing Williams for long enough. That might also be more difficult, however, because her ranking has now dropped outside the top eight.
Even Radwanska can't figure out the reason she doesn't do better on clay. The surface should complement her variety and creativeness, but it doesn't give her extra sting on her shots, and that might be what she really needs. Her best French Open result was a quarterfinal last year, and the 25-year-old plays so much she tends to be injured and exhausted going into it. Will she do that again this year? If she doesn't, and gets a good draw at one of the big events, then she might finally produce a significant result during this portion of the season.
5. Ana Ivanovic
The 2008 French Open champion has not excelled on clay -- or anywhere -- since, but her results this year include two tournament victories and a win against Williams at the Australian Open. A good showing at a big event would be the next step.
The Serb's game is well-suited to this surface, as long as she is striking the ball and moving well. After her defeat in Charleston, Jankovic said she was still getting used to the fitness and long points required on clay. If she does, she could be tough for the other top players. But after returning to the top 10 last year, the former No. 1 hasn't had a big result this season.
7. Simona Halep
The Romanian has continued to move up after reaching the top 10 this year and doesn't mind the clay. She reached last year's semifinals at Rome, and she could cause a few upsets or make a run at one of the big events again. But injuries are also starting to affect her after so much play, and she needs to be move properly to be able to implement her game.
Her counterpunching game should transition well to clay, but at 20, she lacks experience on it and may not move as well.
After reaching the semifinals of the Australian Open to become the breakout player of the year, she has had a few tough tournaments and a few good results. Doing well at some of the clay events would begin to show that she can be consistent during an entire season, the next requirement for becoming a top player.
Question marks
After injuring her foot in Australia, she returned unprepared at Indian Wells and then said she would not come back until fully healthy. That means she might not play that many events, especially since she has shown a tendency to get injured on clay.
A former Madrid champion, Kvitova has showed that she can succeed on this surface as well. After a slow start, she has had better results in her past few events, but it's still hard to know what to expect.
With the exception of Flavia Pennetta, the veteran Italians have barely won matches this year. Errani is 12-10 and Vinci is 2-10 (as is Francesca Schiavone), so they look unlikely to repeat their good clay-court runs of the past two years unless they improve quickly.
She had some decent results at the Australian events, where she usually wobbles under local pressure, but hasn't won two matches in a row since. But her game works so well on clay, the former French Open finalist is still a challenge for even the top players, though she may lack the confidence to win a lot of matches back-to-back.