Picking a grand slam winner is never an easy task but due to the competitiveness on the WTA Tour, the Australian Open really is wide open.

Over the past two years there have been eight different winners of the major women's tournaments, starting with Serena Williams' 23rd grand slam title in 2017 and finishing with Naomi Osaka's triumph at Flushing Meadows.

All of the former champions will be in action in Melbourne next week – injury permitting – and are likely to fill the top sections of the betting market.

However, if history has taught us anything it is to expect the unexpected at grand slams, so seeing a ninth different champion should not be discounted.

So who could realistically challenge the likes of Serena, Simona Halep, Caroline Wozniacki and Angelique Kerber for the title at Melbourne Park? We take a look at five contenders.

Elina Svitolina

Svitolina came into 2019 on the back of the biggest win of her career at the WTA Finals, a fitting end to a year that saw her finish inside the world's top five for the first time.

The 24-year-old has picked up valuable "big-match experience" in the last two years, winning all four of her Premier 5 finals – including the Internationali d'Italia against Halep in May.

Her successes in Singapore and Rome were among four titles in 2018 – she also won in Brisbane and Dubai, while she secured her best Melbourne finish as she reached the last eight.

She suffered a surprise defeat at the Brisbane International earlier this month as she was beaten by Aliaksandra Sasnovich, but Svitolina remains a strong bet to go far over the next fortnight.

Karolina Pliskova

Victory at the Brisbane International gave Pliskova a superb start to 2019 and she will hope it can continue in Melbourne – where she has been a quarter-finalist in the last two years.

Pliskova has been in the world's top-10 for the past three seasons but breaking through to win a grand slam remains something she has yet to do.

Her qualities from the baseline undoubtedly make her an Australian Open contender, but she must find some consistency if she is to become the ninth different champion in a row.

Madison Keys

Since reaching the final of the 2017 US Open final, Keys has been a consistent grand slam performer but taking that final step to be crowned a champion continues to elude her.

Keys is one of a number of promising American players on the WTA Tour at the moment, joining the likes of Sloane Stephens, Danielle Collins and Coco Vandeweghe in stepping out of Serena Williams' shadow.

Stephens denied Keys her first grand slam title at Flushing Meadows, though Melbourne has also been a happy hunting ground, reaching the semis in 2015 and the last-eight 12 months ago.

Injuries hampered her progress in 2018 but expect her to be knocking on the door in the latter stages of the competition.

Petra Kvitova

While the other names on this list have yet to taste grand slam success, Kvitova already has two Wimbledon crowns.

But her successes came before the horrific hand injuries she suffered in December 2016 trying to fend off robbers in her flat.

Having returned to the Tour, even being considered as a grand slam contender is a huge achievement, but Kvitova's inclusion is not a sympathy one.

While results may not have gone her way all the time, Kvitova still shows moments of quality that other players can only dream of and if she can find her rhythm a deep run in Melbourne should not be ruled out.

Aryna Sabalenka

Sabalenka enjoyed a breakthrough year in 2018, the 20-year-old surging up the rankings after 43 wins on the WTA Tour.

Her performance in Wuhan was a particular highlight as she raised her level to see off Carla Suarez Navarro, Dominika Cibulkova, Ashleigh Barty and Svitolina on her way to the title.

Wins over Garbine Muguruza and Caroline Garcia followed in Beijing, and Sabalenka has already got her hands on some silverware this year in Shenzhen.

She may have lost to Kvitova in Sydney but it was a battling display, and with her power and aggression the Belarusian could be a dark horse in Melbourne.