Nadal's career contains curious parallels to Courier's

	Rafael Nadal has had mixed success since winning the 2006 French Open. On Tuesday, he withdrew from the Sydney International because of a groin injury. Alain Mounic/US PRESSWIRE
	MAILBAG Jon Wertheim will answer questions from SI.com users in his mailbag every Wednesday. Your name: Your e-mail address: Your home town: Enter your question:

Do you think Rafa Nadal's career may follow a similar arc to Jim Courier's? Both made their names by imposing their gritty, physical games on opponents. This led to early success for both, especially at Roland Garros. But Courier's career peaked early as other players began to figure out how to play (and beat) him. It appears that Nadal is in a similar situation. Maybe I should wait until after the clay season to make this metaphor, but after his loss to Xavier Malisse, Rafa looks to have lost some momentum.
-- Jay Lassiter, Philadephia

Let's not forget that Courier won four majors and spent some quality time at No. 1. You could do a lot worse than following that arc. That said, since Wimbledon 2006, Nadal's results have, undeniably, been disappointing. He has obviously been off his preferred surface and banged up by a variety of injuries, most recently a groin issue that prevents him from playing Sydney this week.

It stands to reason that, as Nadal has gotten older, other players have figured out how to beat him. They've gotten used to his singular game and sidewinding lefty style. Tomas Berdych and James Blake are among those who realize that they can hit through Nadal and attack both his backhand and second serve.

But I think -- and maybe this is where the Courier analogy should come in -- a lot of the problem is that Nadal's "ground-and-pound" game is so physical. Not only is he putting a lot of pressure on his body, but when his body is anything less than 100 percent it really impacts the effectiveness of his play. Unless he can play every match at night, when the court slows down, I don't see him snapping his slump in Australia. But maybe he lightens his schedule (the dude reached the doubles final last week in India!) and recuperates in time for Indian Wells.

I guess Hong-Kong proved you wrong so far on Kim Clijsters' "lame duck" status. How may mailbags ago was it that you wrote anything relevant about her, let alone something nice? If I asked you to name the one quality in which she excels on the court, which would you pick? 
-- Reinhart Papen, Bonheiden, Belgium

I'll bite on this question, in part because I feel bad about slighting Clijsters, one of the genuinely nicest athletes I've ever met. So I'll take her movement and point-prolonging defense. And while I'm not inclined to read much into exhibition results (didn't Pete Sampras beat Andy Roddick a few weeks ago?), her play in Hong Kong should fire her with some confidence heading to Melbourne.

As you can tell, I have real ambivalence about Clijsters. How can you possibly knock an athlete for never developing a hardened crust, for setting a retirement date and sticking to it, and for never letting "what I do" become "who I am"?

On the other hand, we want to feel like athletes are invested in their careers and performances, and that they care deeply about the results -- that, to cite Amelie Mauresmo, they're willing to die on the court. With Clijsters -- particularly lately -- I come away with an empty feeling. Sure, she'd like to win. But if she loses, she gets to go home, see her boyfriend, play with her dogs. Hard to see how that attitude can prevail over the fight of, say, Maria Sharapova or Justine Henin-Hardenne.

Just what is it about the Kooyong exhibition tournament that enables them to attract the world's top tennis players year after year? At the very least, there are no ranking points to be gained, something I think most players would find important especially at the beginning of the year. 
-- Andy, St. Paul, Minn.

It is the ideal exhibition. Players get paid to acclimate to the conditions (and time zone) of the forthcoming Slam. They are guaranteed three matches against top opposition and compete at a venue miles from Melbourne Park. With those perks, it's easy to see why the draws are so strong.

I'm don't understand the requests for names on the backs of players' shirts. People who really can't tell the two apart after a few sets need to go home. It's not like it is confusing with a whole team of tennis players on the court at the same time.
-- Diane, New York

A few of you asked about this. The uniform isn't about helping to identity who's who. It's about merchandising: providing fans with some cool regalia and creating some additional exposure for the sport. Walk the streets of any city from Savannah to Shanghai and you'll find folks wearing Michael Schumacher caps and Yao Ming jerseys and Michael Vick do rags. Why can't tennis do the same? Really, who among us, wouldn't throw down some heavy timber for a jersey that had "Federer" or "Jankovic" on the back?

Does Anastasia Myskina have the credentials for the Hall of Fame if her career ended today? I love her game and I hope she wins another major soon when she's totally healthy.
-- Keith J., Minneapolis, Minn. 

Even a terminal softie like me has to draw the line somewhere. I like her game too, but, boy those are some slim credentials. One Slam (and, though no fault of her own, she did not exactly take down a world-beater in the final). No other major finals. No top ranking. Only nine other titles. I'm not only voting "nyet" here, I'm going a step further: letting Myskina in (again, with no credentials beyond today) is basically saying, "Anyone with a solitary Slam gets in."