And Rohan Taylor says it now decides Australia's swimming fate at the Tokyo Olympics.

"On paper, it looks like we are (looking good)," Taylor said ahead of Saturday's first session at the pool.

"But you know when you come to this competition, it's about who has the competitive IQ to perform under pressure.

"The American system breeds competitive athletes, their whole college system, the best competitive people come out of the top.

"But we believe this year we have some really strong competitive, strong mentally competitive athletes."

Of the 14 individual Olympic swimming races, an Australian ranks top in seven and an American top in five.

And Australia boast exceptional strength in relays, led by a women's 4x100m freestyle team seeking to win gold for a third Olympics in a row.

But Swimmming Australia head coach Taylor dodges any medal predictions.

The nation's best Olympics at the pool is eight golds at Melbourne's 1956 Games.

For all Australia's strengths, Taylor is wary of the US, as is customary, flexing its muscles at an Olympics.

"The Americans have proven historically at the Olympics that they perform," Taylor said.

"So for us, you know they're the standard that were striving for. And they rightly so have deserved that."

The American dominance at Olympic pools is sport's great stranglehold: 246 golds among 549 medals overall.

Next, Australia with 60 golds among 192 medals.

The Americans amassed 16 swimming gold medals in each of the past two Games - but Michael Phelps is now watching from the television commentary booth, retired with 23 golds.

There's a sense the competition could be the most open since the end of the Cold War, with Australia's team holding several aces.

Sprinters Emma McKeon and Cate Campbell, backstroker Kaylee McKeown and middle-distance freestyler Ariarne Titmus are among those with world-best times entering Tokyo.

Australia's 4x100m freestyle relayers - Cate and Bronte Campbell, McKeon and Madi Wilson - are overwhelming favourites.

Cate Campbell, after being an Australian flagbearer, will sit out Saturday night's relay heats, saving her energies for Sunday's final.

So may McKeon, who on Saturday night marks the start of her hectic program with the 100m butterfly heats.

McKeon, the nation's most successful athlete at the 2016 Rio Games with one gold, two silvers and a bronze, and Olympic debutants Brendan Smith and Se-Bom Lee (400m individual medley heats) will be among the first Australians in the pool.

Medal fancies Elijah Winnington and Jack McLoughlin in the 400m freestyle and Zac Stubblety-Cook in the 100m breaststroke will also contest heats.

Australian Associated Press