A spot is up for grabs on the Australian Swimming Olympic team over the next six days, with the national trials beginning in Adelaide today.
Australia sets a high benchmark for qualification, so any swimmers who make the squad when it's announced next Thursday will be world-class. They need to be.
The Olympic Games are the pinnacle of world swimming and the time when Australians tune in en masse for what is traditionally our strongest Olympic sport.
Australia won three gold medals including two individual golds to Mack Horton and Kyle Chalmers at the last games, plus a victory to the women's 4 x 100m sprint team.
The overall tally of three golds, four silvers and three bronze medals was less than the Dolphins and the Australian Olympic Committee hoped for and so, perhaps to lower expectations this time around, no specific medal targets are being set.
That said, Australia's swimmers go into these trials with some world class athletes and exciting new stars expected to push for gold in Tokyo.
And this time around, it's the women who look best placed to pick up the medals.
But predicting success is all the more difficult this year because arch-rival, the United States, is holding its swimming trials at the same time — assessing form based on performances earlier this year could go out the window during the next week.
With that caveat in place, who are the swimmers to watch out for?
Kaylee McKeown
The hype around this Queensland teenage backstroker and medley swimmer has been enormous and for good reason.
She holds the fastest times in the world this year and the Australian records in both the 100m and 200m backstroke.
Last month, McKeown came within .06 seconds of the 100m world record with a blistering swim in Sydney – fast enough to become the second quickest of all time.
Her main competitor in both distances will be the dual US world record holder and world champion, Regan Smith, but on current form, McKeown is a real chance to knock Smith off.
McKeown is also in blistering form in the 200m individual medley, with the second-fastest time in the world this year.
Emma McKeon
Emma McKeon has long been upstaged by former 100m freestyle world record holder Cate Campbell, but this year has stepped out of the shadow and is in arguably the form of her life.
McKeon has the first, third and fourth-fastest times this year in the 100m, but Campbell is still thereabouts with the second, sixth and seventh-fastest times.
Campbell was devastated after going into the 100m final at Rio as the fastest qualifier only to finish sixth and will be keen to make amends in what will likely be her fourth and last Olympics.
The 100m race between McKeon and Campbell on Wednesday night of the trials will be the highlight of the meet.
As it is, the blistering form of the two swimmers has Australia well placed to defend the gold medal it won in the women's 4 x100m relay in Rio.
McKeon is also performing strongly in the 100m butterfly (for which she holds the Australian record) with the fifth-fastest time in the world this year.
She's also swimming strongly in the 200m freestyle, with the seventh-fastest time this year.
Cate Campbell
Aside from the battle in the 100m freestyle, Campbell will be looking to qualify in the 50m sprint.
She's the Commonwealth and Australian record holder over the distance and holds the third-fastest time of the year.
Ariarne Titmus
Ariarne Titmus looked to have the swimming world at her feet when she did something that never happens – beat American superstar and World Record holder, Katie Ledecky, in her favourite event, the 400m freestyle final.
To put it in some context, Ledecky holds the seven fastest times in history over 400m and nine of the top 10. Only Titmus has spoiled her perfect record with the eighth-fastest time.
Unfortunately, Titmus has battled shoulder injuries over the past year, which has interrupted her preparations for the Olympics, but she is once again posting strong times.
Titmus has the third-fastest time this year in the 400m free, the fifth-fastest time in the 200m and the eighth-fastest in the 800m. But in all cases, she is behind the all-conquering Ledecky.
Fun fact: Ledecky has the top 24 times in history over 800 metres.
The Olympic trials will be a great test of whether Titmus has put her injury behind her and can once again compete with the astonishing Ledecky.
Kyle Chalmers
Kyle Chalmers seemingly came from nowhere to upset Cameron McEvoy in the 100m freestyle at the Rio Olympics.
He'll be looking to defend his Olympic crown with a strong showing at the trials and despite having a shoulder operation last year, looks to be finding some reasonable form.
He blitzed his rivals in the Australian Championships in April and while his time in the 100m is still only the 26th-fastest this year, over the sprint, the difference between the top few is measured in the hundreds of seconds.
His best time of 47.08 was enough to earn a silver medal at the last World Championships, behind his arch-rival from the United States, Caeleb Dressel, and he'll be keen to lay down a marker at these trials.
Mitchell (Mitch) Larkin
The other Australian male with a serious chance of an Olympic medal is a veteran going for his third Olympics, Mitch Larkin.
Larkin holds the third-fastest time this year in the 200m individual medley as well as the second-fastest time in his pet event, the 200m backstroke, in which he won a silver medal at Rio.
His problem is that the heats for both of these events are being held on the same evening during the Olympic Games, which has led to some soul searching about which event to choose.
Yesterday, he announced he'd be concentrating on the individual medley.
"I have been hitting my head against the wall for a number of months trying to make that decision," he said.
With the legendary US swimmer Michael Phelps now retired, Larkin thinks the IM is his best chance for a medal.
"I have never swum at an Olympic Games in a medley event, which gives me a lot of excitement," Larkin said.
Matthew Wilson
It took a world record to beat Sydneysider Matt Wilson in the men's 200m breaststroke at the 2019 World Championships in South Korea, and his time that day still ranks as the third best in history.
But Wilson's form since has been patchy – he has just the 34th-fastest time of the year.
It's another Australian, Zac Stubblety-Cook who is showing the better form with the fifth-fastest time of the year recorded in Sydney last month.
Stubblety-Cook beat Wilson in the 200m breaststroke at the Australian Championships in April, setting up a fascinating race which should be one of the highlights of the trials.
Mack Horton
Mack Horton was one of Australia's two individual gold medallists at the Rio Olympics, winning the 400m freestyle against his arch-rival, China's Sun Yang.
Three years later, Sun beat him at the World Championships, leading to Horton's famous protest where he refused to share the podium because of Sun's outstanding doping charge.
Whether Horton even gets to defend his Olympic gold medal is very much in question – his form so far this year has been terrible. His best time this year places him at a lowly 113.
The Australian setting the pace is Elijah Winnington, who's recorded the ninth-fastest time of the year and is within one second of the fastest, Russian Martin Malyutin.
Horton is a proven champion, so the trials will be a great test of his ability to put up a performance when it's needed, otherwise the baton of the 400m king will be handed to Winnington.
Of course, the names of other athletes will announce themselves over the next six days, which is the excitement of these trials coming so close to the Olympics.
The form our swimmers show at the trials will also give us a good guide on how Australia can expect to go in the relay events, which traditionally have been one of Australia's strongest chances.
The women's 4 x 100m and 200m and the medley relays at this stage look to be the best opportunities to win medals.
The Paralympic team will be announced on Wednesday night, and the Olympic team on Thursday night.
The trials will be streamed by Amazon Prime.