She is the oldest world No 1 in the history of women's tennis and many believe she is the greatest player ever to have picked up a racket, but Serena Williams' hunger remains undiminished. The 31-year-old American's domination has probably never been greater as she faces Victoria Azarenka in the final of the US Open here today.
There have been blips along the way – most notably defeats by Sloane Stephens in the quarter- finals of this year's Australian Open and to Sabine Lisicki in the fourth round at Wimbledon - but the evidence of the last 15 months suggests that Williams is a better player than ever. She has won 13 of the last 18 tournaments she has played, including Wimbledon and the US Open in 2012, the Olympics, the WTA Championships and the French Open.
With 16 Grand Slam singles titles to her name, the question now is whether Williams can become the most successful female player of the Open era.
The record for Grand Slam singles titles is held by Steffi Graf, who won 22. Chris Evert, who is tied in second place alongside Martina Navratilova with 18, believes that Williams has time on her side, given that she has always played fewer tournaments than most and has had periods away from the game through injury.
Williams insists that she is not motivated by records. "I never really want to focus on the numbers," she said. "I started playing tennis not to be the greatest but just because I had a racket and a dream.
"Now people are talking about what I could achieve, but I'm just not there yet. To me people like Chris Evert, Martina Navratilova and Steffi Graf are the ultimate icons in the history of women's tennis. I'm just that girl with the racket and a dream. I'm just playing for that."
If there is anyone who can stop Williams' assault on history it could be the woman who will face her today for the second US Open final in a row. While the world No 3, Maria Sharapova, who missed this tournament with a shoulder injury, has lost her last 13 matches to Williams, Azarenka has turned around a similar record. After losing nine matches in a row against Williams, the world No 2 has won two of their last three meetings.
After those victories in the finals in Doha and Cincinnati this year, Azarenka believes she has a real chance of beating her in the first US Open final for 10 years to feature the world's top two players. The 24-year-old from Belarus, who has won two Australian Opens, went close last year, having served for the title and getting within two points of victory before Williams won the deciding set 7-5.
Williams believes she brings out the best in Azarenka. "I have seen her play other players and, when I play her, I am playing a totally different player," she said.
Azarenka said the key to beating Williams was to take her out of her comfort zone by scrapping for every ball. "You've got to fight," she said. "You've got to run, you've got to grind, and you've got to bite with your teeth for whatever opportunity you have. She's an amazing player. She's the greatest of all time."
Nevertheless, if Friday's semi-finals are any sort of form guide, Williams is the clear favourite. The American beat Li Na 6-0 6-3, sweeping aside the 2011 French Open champion with the sheer power of her game.
While Williams has yet to drop a set here and has lost only 16 games in her six matches, Azarenka was taken the distance by both Alize Cornet and Ana Ivanovic.
She reached the final by beating Flavia Pennetta 6-4 6-2 but dropped her serve five times in the match. The Belarusian is unlikely to get away with that kind of inconsistency against the player with the best serve in women's tennis.