Serena warns her best is yet to come

Serena Williams might have won nine Grand Slams but she warned today she plans to be around for years to come with her best tennis still ahead.

The 27-year-old is angling for a fourth Australian Open title after winning here in 2003, 2005, 2007.

"I feel like I'm trying to improve on my game and get better. You know, I feel like I just want to continue to get better, so I haven't reached my best yet," she said.

Only a few select women, including Steffi Graf, Martina Navratilova and Chris Evert, have won more major titles although Williams still has some way to match Margaret Court, who collected 24.

But she still has time on her side.

Asked how long she would continue playing, she replied: "Well, hopefully a really long time."

Williams added that she felt she was a better player now than five years ago when she dominated the game, winning Roland Garros, Wimbledon and the US Open in a storming 2002.

"Well, I think that I'm - I don't know. I have to watch old films. I think that I'm on that level, if not better," she said.

"I hope I'm better than what I was five years ago. I would say that I am.

"But a lot of the girls now, especially when they play against me, and probably Venus too, they want to beat the best players and say that I was able to beat them, or me.

"So I feel like sometimes when people play me they play extremely hard, which actually makes me a better player."

Now ranked World No 2 behind Serbia's Jelena Jankovic, Williams opens her campaign against China's Meng Yuan.

If all goes to plan, she has a potential quarter-final against Russian eighth seed Svetlana Kuznetsova and a possible semi-final against either her sixth-seeded sister Venus or fourth-seeded Elena Dementieva.

"I'm actually pretty happy about my preparation. I felt like I got some really good matches under me in Sydney and still with plenty of time to rest and get ready for this event," she said, adding that staying fit was a key task.

"Well, just my consistency both on and off the court and just staying super ready and fit," she said, on how she could improve.

The powerful baseliner with a booming serve returned to World No 1 last year in September for the first time in over five years - the longest gap between No 1 stints for any player ever, male or female.

She held on for four weeks before Jankovic regained the top spot and kept it till the end of the year.

Williams is determined to reach the summit again, with the Grand Slams her major focus this year.

"I'm definitely aiming myself at Grand Slams," she said.

"I want to play my best tennis in the majors. I also want to play good tennis - you know, the tour kind of restructured itself with so many big tournaments like in Madrid and the Asia-Pacific area.

"So with the new exciting tennis, I think I would want to play well at those tournaments too."