There will be no successful defence of the Australian Open from Serena Williams, who announced last week she would play no part in the tournament.

Last year, the seemingly evergreen American claimed the title despite being in the early stages of pregnancy.

With daughter Olympia now brought into the world, Williams has opted to extend her break, saying: "Although I am super close, I'm not where I want to be."

Her absence clears the way for a challenger to make their name, although Serena will surely be disappointed at missing out on an opportunity to re-write another record.

Below, we have taken a look at the most pertinent Opta facts ahead of the first grand slam of 2018. 

SERENA'S SENSATIONAL STATS

Although she will play no part at Melbourne Park over the next two weeks, Williams' sparkling record cannot be ignored.

She has participated in eight Australian Open finals, more than any other player in the Open era and has emerged victorious in seven of the last 15. Her only defeat from those eight appearances came at the hands of Angelique Kerber in 2016.

Her next grand slam victory will be her 24th, equalling Margaret Court for the most of all-time in women's tennis while the 36-year-old will have to wait until 2019 to try and usurp Thelma Coyne Long as the oldest winner of the Australian Open (35 years and eight months in 1954).

NUMBER-ONE MERRY-GO-ROUND TO CONTINUE?

Simona Halep enters the first major of the year as the world's top-ranked player which, after years of Serena dominance, chopped and changed on a regular basis last season.

In fact, ownership of the number one spot changed hands seven times throughout 2017, after having done so only twice in the four previous years.

Halep's rise to the summit came despite the Romanian failing to break her grand-slam duck. Both Halep and Karolina Pliskova reached the top without major glory in 2017; the last time any woman had done so was Caroline Wozniacki in October 2010.

Pliskova and Halep will hope to end their major hoodoo in Williams' absence and the WTA Tour has seen four new grand slam winners in the last two years (Kerber, Garbine Muguruza, Jelena Ostapenko, and Sloane Stephens), three more than in the two years prior (Flavia Pennetta).

COULD A 40-YEAR WAIT END WITH A BARTY PARTY?

Four decades have passed since Australian fans saw a home winner in the women's singles. 

Chris O'Neil was the last victor back in 1978, while Wendy Turnbull's runner-up finish two years later represents the last time an Australian woman reached the final at Melbourne Park.

Could Ashleigh Barty be the one to end that drought? The 21-year-old comes into the tournament as the highest-ranked Australian at number 19, having dropped two places from her career-high 17 late last year.

One woman who has experience of grand slam glory is Samantha Stosur and the 2011 US Open champion can reflect on a strong overall record in WTA finals - she has won four of the last five she's contested; a 2016 loss to Lucie Safarova in Prague the only defeat in that span.