Kim Clijsters

Kim Clijsters was 20 when she became the world No. 1 and the plaudits were mixed with a bunch of aggravation because she had not won a Grand Slam tournament and thus, the prevailing mood suggested, was an undeserving cause.

Press the fast-forward button and Caroline Wozniacki is impaled on the horns of an identical dilemma. When is a No. 1 not a No. 1?

Five of the other seven contestants in the field for the WTA Tour Championships here were asked the leading question Monday — Wozniacki, the 20-year-old Dane, was spared because she has been asked it so many times already and the carcass had been well and truly picked over before Victoria Azarenka enjoyed a good night’s sleep after her victory in the Kremlin Cup in Moscow on Sunday.

Clijsters is 27, a three-times US Open champion and a Mother Superior on the tour as the only player here who has a child (and is reduced to babbling a few words down the phone to Belgium each evening to content Jada, her two-year-old, who is at home with her dad, Brian).

Turn to the individual in women’s tennis for a sense of what it is really like above and beneath the surface (and is best able to enunciate it) and Clijsters is your girl.

“As a child, you are aware of what being the No. 1 means and yet when you get it, nothing really changes,” she said.

“Other people might make a big deal out of it and, of course, it’s an honour and privilege. You want to present yourself well, I certainly did to the kids in Belgium, to have good manners and etiquette, to respect the game. But I never looked at myself and said, ‘I’m No.1, I’m the best.’”

Clijsters said that it is important for Wozniacki to demonstrate consistency. “When [Dinara] Safina became No. 1, she dropped right away but I’m sure Caroline will not fall back, although she’s going to have to reduce the number of tournaments she plays because the business for her is going to start to get very serious,” she said.

“She’s a nice girl, but she has a game that is physically very demanding.

“She isn’t like Serena [Williams] who will hit a lot of winners and aces, she has to fight in every match she plays, which is a good thing, and I think she brings beautiful tennis to the tour.

“She has a good head on her shoulders, she travels with her family as well who will keep it as normal as possible for her so she’s not spending all her time worrying about her ranking.

“She is 20 and she has achieved so much and although she hasn’t won a Grand Slam yet, I don’t think you’ll be asking that question in a couple of years’ time.”

What, one wonders, will we be asking of Clijsters in 2012? She hopes it will involve something along the lines of “what was it like to win Wimbledon?” or perhaps “does having a second child mean you will have to call time now?”

To be ready for us just in case those might crop up, Clijsters has to take infinitely more care of herself and has arrived in Doha in svelte condition.

There’s a hint of a blush as you say that, but the combination of the joy of motherhood and sadness at the loss of her father, Leo, to cancer almost two years ago — her mother, Els, had a liver transplant recently — has made looking after No.1 more than a matter of professional and domestic routine.

“I’ve always been interested in eating healthy and I’m very strict, especially when I’m on the road,” she said.

“I’m not for ever counting calories, but I make sure I eat right. I have been through negative things in my life and I try to look on food as a positive.”

“Take coming here. The heat is something you don’t have time to adjust to. I make sure I’m completely hydrated as soon as I wake up: that’s a big bottle of water and salt tablets. Those are extremely important. I’m talking like a mother, but you must eat your vegetables. You can go through so much stress trying to digest bad foods and then struggling to deal with the heat.”

This is the prestige end to a season in which, Clijsters said, she has noted a change in the way the leading women players interact. There are fewer embittered people around, she says.

“What I like about the game is the spread of personalities,” she said.

“We’ve seen the guys hang out together for years and it’s something that’s growing on our side. It’s an individual sport but there’s more of a team spirit, which sends out a good vibe to the outside world and to potential sponsors” said Clijsters.