It is unsurprising that a player with the reputation and history of Serena Williams is the favourite to win this title, and the signs were good as she won three singles matches from three in the recent Hopman Cup.
Yet twice in 2018, at Wimbledon and the US Open, she progressed to the final of Grand Slams before running out of steam to lose in straight sets.
To back her as favourite would be risky until she has proved that she has the stamina to win majors again.
Fourth-favourite Elina Svitolina immediately stands out as another candidate for this title.
The Ukrainian ended last season by lifting the WTA Finals title, more of an indicator of her standing than a defeat to Alisksandra Sasnovich in the second round of the Brisbane International a fortnight ago.
She made the quarter-final of this event last year, while the biggest fish in her half of the draw is Simona Halep, who has suffered badly from a back injury recently.
Aryna Sabalenka has been heavily backed since winning the Shenzhen Open at the start of the month.
The 20-year-old was beaten in the first round of three of four Grand Slams last season, though, including this one. She is not worth backing until we know a little more about how she will deal with the latter stages of majors.
Second-favourite Angelique Kerber won this title in 2016, reached the semi-finals last season and won Wimbledon in June.
A heavy defeat to Petr Kvitova at the Sydney International this week might be a concern, but she could be worth considering.
Best of the rest
Ashleigh Barty was impressive form in Sydney this week, emerging as a serious contender for the title in Melbourne in the next fortnight.
The home favourite has improved at slams in the last year, progressing to a personal-best fourth round at the US Open in September and claiming the title in the women’s doubles.
Sloane Stephens has already suffered a disappointing defeat this season, losing to Yulia Putintseva in the second round in Sydney.
Her inconsistency is demonstrated by the fact that her four slams last season resulted in a final, a quarter-final and two first-round exits, though, so she can’t be ruled out.
In a top half of the draw packed full of potential success stories, Garbine Muguruza – who has reached a major semi-final in each of the last four seasons, including two titles – is a nice bet to come through.
Qiang Wang is an outsider to watch, having reached the semi-finals of her last six events of 2018, including victories over Madison Keys and Muguruza in the WTA Elite Trophy.
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