Federer, Roddick rock the first quarter

With the United States' major hard court tournaments at Indian Wells and Miami concluded, the first quarter of the tennis season is now complete as the competitors head to the clay.

These are the letter grades for most of the tour's top players. Notables who have been injured for a long stint (Juan Martin Del Potro, Nikolay Davydenko and Dinara Safina) aren't rated.

A: Roger Federer, Andy Roddick and Serena Williams

Federer and Serena get top grades despite winning only the the Australian Open. Given that it's by far the most significant event of the first quarter and that despite heavy competition they managed to add to their tour-leading Grand Slam titles (Federer with a men's record 16 and Williams with 12), they can be given passes for February and March.

Serena, whose knees are aching again, didn't play another event, while Federer, who was ill in early February, suffered teeth-clenching losses at Indian Wells and Miami. Whatever the case, expect both of them to come into the Roland Garros with huge goals, as it's the majors that are virtually their sole focus now.

Roddick, who has transformed into a thinking man's player, didn't go as deep Down Under, suffering a sciatic nerve injury and falling to Marin Cilic in the quarterfinals, but he won Brisbane, reached the finals of San Jose and Indian Wells and knocked off Rafael Nadal and Tomas Berdych to win Miami, his first Masters Series crown in three and half years. With newfound confidence in his flat forehand and a developing return game, he's back in the mix again at the age of 27. As his game isn't built for clay, he'll have to wait until Wimbledon to prove that he's a truly elite player again, but he'll be the most feared man on the lawns apart from Federer.

B-plus: Kim Clijsters, Justine Henin, Venus Williams, Rafael Nadal, Tomas Berdych and Marin Cilic

Yes, Clijsters suffered a shocking third-round loss to Nadia Petrova at the Australian Open and was too passive against Alisa Kleybanova at Indian Wells. But give her huge credit for pulling off two third-set tiebreaker wins over arch-rival Justine Henin at Brisbane and Miami, and also for destroying Venus Williams in the Miami final. Don't expect the broad-shouldered Belgian to win every tournament she plays, but do expect her to put up some amazing numbers by year's end. Right now, with Serena on the shelf, she looks like the most complete player on tour.

While Henin has yet to win a tournament in her comeback, she had an amazing run to the Aussie Open final and played Clijsters very tough despite having massive trouble with her serve and some questionable strategy. She's only three months into her comeback, has always loved the clay and she'll be the favorite to win her fifth French Open title if she's healthy.

After a horrific quarterfinal loss to Na Li at the Aussie Open, Venus put together the best two-month stretch she's had in six years, winning Dubai and Acapulco and reaching the Miami final. But as evidenced in the Miami final, at the age of 29, Venus may not have the legs to win another Slam off grass.

It could be argued that Nadal deserves a lower grade. But given that his sore knees have yet to fully heal, tight losses to Murray, Ljubicic and Roddick aren't anything to be overly concerned about, especially since the Spaniard played extremely well in spurts. But what is troubling to his fans is that Nadal doesn't have full confidence in his knees yet, which may hinder him on clay.

Berdych was a revelation at Indian Wells and Miami, finally getting another win over Federer and blasting Soderling to reach the Florida final. At 24, he's matured to the point where he no longer hides his weapons at closing time. He may just realize his top-five potential sometime later this year.

The young Cilic was sensational in January and February. And while he won't do much damage on clay, he'll continue to be a huge threat to the rest of the top 10 if he can keep himself fit and not overplay.

B: Caroline Wozniacki, Jelena Jankovic, Samantha Stosur, Agnieszka Radwanska, Robin Soderling, Ivan Ljubicic, John Isner, Jo-Wilfried Tsonga, Fernando Verdasco and Juan Carlos Ferrero

Despite ascending to No. 2, Wozniacki still has miles to go before she enters a major as a favorite. The 19-year-old Dane competes well, her defense is terrific and her backhand is a major weapon, but she'll continue to be an underdog against the veteran elite if she doesn't improve her forehand.

Jankovic is finally headed in the right direction again after her title run at Indian Wells, while doubles standout Stosur has done a fine job focusing on her singles and cracking the top 10. Radwanska will never be a world-beater, but she's smart and resourceful and is actually pushing herself again.

Ljubicic has really committed to playing his best tennis past the age of 30 and put together all the right combinations in winning Indian Wells. Soderling has also shown that his run to the 2009 Roland Garros final was no fluke by putting up consistent results since then. Isner, the towering American, is on the verge of cracking the top 20 but is also a work in progress.

Tsonga is great fun to watch and had some inspiring wins in Australia where he reached the semis of the Oz Open, but will he ever put it all together? Spain's Fernando Verdasco and veteran Juan Carlos Ferrero both made decent progress on hardcourts and should hang in the top 15 all year long.

C-plus: Elena Dementieva, Yanina Wickmayer, Li Na, Zheng Jie, Novak Djokovic, Andy Murray, Mikhail Youzhny and David Ferrer

Give China's Zheng Jie and Li Na credit for reaching the Aussie Open semis, but they have done little since then. Dementieva won Sydney and the Paris Indoors, but flamed out at the big events. Young Belgian Yanina Wickmayer is super talented but tends to press.

Andy Murray should have received an “A” after his run to the Aussie Open final, but he was shaky there and did nothing of note afterward, saying he's lost the joy of playing. That's a bad sign for a relatively young player. Other than scoring two wins in Davis Cup and winning Dubai, Djokovic has been nothing but disappointing and doesn't show the look of a big match player often enough. It's hard to see veterans David Ferrer or Mikhail Youzhny progressing much further.

C: Maria Sharapova, Victoria Azarenka, Melanie Oudin, Gael Monfils, Sam Querrey and Gilles Simon

Former No. 1 Sharapova just can't seem to get her career kick-started again after shoulder surgery. She lost in the first round of the Aussie Open, won a small tournament in Memphis and then injured her elbow in a loss at Indian Wells, which forced her to pull out of Miami. If she can't get healthy, there's no way she'll be able to contend for Slam titles again.

Azarenka just keeps coming up short at the major events and really needs to display a smarter brand of tennis. Oudin rallied at Fed Cup and the Paris Indoors, but her performance in the quarter's big three events was sub-par. Monfils just can't seem to stay healthy or work out his technical kinks, while Simon seems like a one year, top-10 wonder. Querrey played well indoors, but has been found wanting on outdoor hardcourts.

D: Svetlana Kuznetsova, Ana Ivanovic, James Blake and Radek Stepanek

Kuznetsova, the defending French Open champion, has had a terrible year, winning consecutive matches only twice in five tournaments so far. Ivanovic dropped from No. 1 to No. 57 in less than two years and hasn't had a solid tournament in more than 12 months. Blake looked like he was ready to revive at the Aussie Open when he took Del Potro to five sets in the second round, but is now ranked outside of the top 50 and has faded again.

After reaching the Brisbane final at the start of the year, Stepanek plunged and will take at least two months off due to fatigue syndrome. Hopefully he'll recover sufficient energy for his July wedding to the now-retired fellow Czech, Nicole Vaidisova.

F: Nicole Vaidisova and Wayne Odesnik

One player quits at the age of 20 (Vaidisova) and another (Odesnik) pleads guilty to importing human growth hormone into Australia just before the tournament in Brisbane in January and continues to play on. Why and why?