Can Roger Federer maintain his late-career renaissance? Will Rafael Nadal continue to turn back the clock? The 2018 Australian Open may provide some answers.
Last year's final was like stepping into a time warp as tennis' two most decorated stars battled it out over five gripping sets in the final.
Federer got the better of his opponent on that occasion and the Swiss will be strongly fancied to retain his title this year as he chases yet another entry into the history books.
His cause is aided by the absence of five-time losing finalist Andy Murray, who has undergone hip surgery, while Novak Djokovic is another man who has been plagued by injury as he looks to avenge last year's early exit.
Below, we have taken a look at the most pertinent Opta facts ahead of the first grand slam of 2018.
FEDERER THE FIRST MAN TO 20?
Federer's defeat of Nadal last year was his 18th major triumph of a glittering career. He made it 19 at Wimbledon and a successful defence of his crown in Australia would see him become the first man to win 20 grand slam singles titles.
Should he succeed, Federer will move onto six Australian Open crowns – the joint highest tally of any man alongside Djokovic and Roy Emerson.
Only at Wimbledon (eight) has he lifted a grand slam trophy on more occasions, while the Swiss can point to his Melbourne Park record with confidence heading into this year's event. He has reached at least the semi-final stage in 13 of the last 14 Australian Opens (2015 being the exception).
His longevity has been marvelled at far and wide, underlined by the fact that his 2017 victory came 13 years after his first. No player has won multiple Australian Open titles over a longer period in the Open era.
WHAT OF THE REST OF THE BIG FOUR?
Murray's injury-enforced absence at least increases the chances of seeing a new name in the final. Either he or Rafael Nadal have been runner-up in each of the last eight showpieces, Murray losing five and Nadal three.
Nadal's five-set defeat to Federer last year will go down as a true epic between two sporting greats, but the longest grand slam final in the Open era belongs to Djokovic and Nadal, who battled for five hours and 53 minutes in 2012.
The Spaniard, after a couple of barren years in 2015 and 2016, contested three of the four grand slam finals in 2017. He is seeking consecutive major wins for the first time since winning the French Open, Wimbledon, and US Open in 2010.
Nadal won 23 matches at grand slams in 2017, the most since his 25 in 2010. By contrast, Djokovic is returning from injury and hopes to avoid a repeat of last year's second-round defeat to Denis Istomin – his worst result since bowing out at the first hurdle in his first appearances in 2005 and 2006.
AUSSIE, AUSSIE, AUSSIE, OI, OI, OI!
Nick Kyrgios' success at the Brisbane International last week has perhaps prompted optimism among Australian fans of a long-awaited home winner this time around.
Indeed, many Aussie supporters may not have been alive to witness the last occasion. Not since Mark Edmondson in 1976 – against compatriot John Newcombe – has an Australian man lifted the title.
There has been little to cheer since the turn of the century and the last time an Australian made it to the men's final at Melbourne Park was Lleyton Hewitt in 2005.
Since Edmondson's win 42 years ago, 20 different players have claimed the crown.