Fast closing in on 31, Li Na will have to defy history if she is to achieve her stated aim of cracking the world's top three this year.

That's because players are usually starting to slow down and in the women's game in the modern era only Margaret Court, Chris Evert and Martina Navratilova have won a major after reaching that age, and they are among the game's greats.

Current Wimbledon and US Open champion Serena Williams did win those two most recent of her 15 grand slam singles titles just before reaching the age in September last year though, and appears as big a threat as ever at the majors.

While prolific major winners Court, Evert and Navratilova were all still factors at the majors into their 30s, and Williams remains a force, Steffi Graf won her 22nd and last major title just before she turned 30 in 1999 at Roland Garros and promptly retired within months.

Court, who won an amazing 24 grand slam titles in her long career including a staggering 11 Australian Opens, claimed three of those crowns in the year she turned 31.

But while her haul included the last of her Australian and French Opens in 1973, it was only her victory at the US Open that came after she had reached that age.

A winner of 18 majors, with seven French Opens and six US Opens among them, Evert won her last two grand slam titles at Roland Garros in 1985 and '86, either side of her 31st birthday in December 1985.

Navratilova also won 18 grand slam singles titles, the 17th at the US Open in 1987 before she turned back the clock with one last hurrah at Wimbledon in 1990 when she was closing in on the age of 34.

Given all of the above, Li's stated goal that she wants to halve her current ranking at number six would appear perhaps a little ambitious just a month before she turns 31.

But giving her confidence it is possible is that she won the 2011 French Open even though she admitted after her third-round win over Romanian Sorana Cirstea on Friday at the Australian Open that one of the biggest battles she has faced throughout her career is her lack of self-belief at times.

Since linking up with Carlos Rodriguez last August, Li has had some strong results including her title triumph in Cincinnati later in the year.

And encouraged by Justine Henin's former coach to stop 'fighting against myself', Li is starting to believe a lot more in her game.

Time will tell whether Li does in fact replace one of Victoria Azarenka, Maria Sharapova or Williams in the top three but to do so she would almost certainly have to win at least one of this year's grand slams, which history says is unlikely at her age.


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