There is no need for Missy Franklin to imitate Mike Tyson and take a chunk out of her rival Emily Seebohm's ear. She need not lash her with a whip as a male jockey did to the great Julie Krone. She doesn't have to wag her finger at the Australian as Jimmy Connors once did to John McEnroe.
But not even a spit? Or a stare?
In 300 days or so Franklin, 20, and Seebohm, 23, will try to break each other's heart in the backstroke at the Rio Olympics. They will bring everything they have to ruin each other's dream. So a little animosity is understandable. Instead we get this: They sit at a press conference in Singapore and giggle.
"We're friends," beams Seebohm later. "And it's special racing your friend," grins Franklin afterwards.
Is this a rivalry or a reunion?
Not every sport needs to be like swimming but it's nice that swimming isn't like every sport... For now it's just natural and charming to see two rivals smiling and not swearing at the mention of the other's name.
Franklin has four Olympic golds and Seebohm has two. The American beat the Australian to second place in the 100m backstroke at the 2012 Olympics and the 2013 world championships. The Australian beat the American to second place in the 200m at this year's world championships. In every way they are close.
Of course, before they race they ... intimidate each other, they try Kyrgios-style gamesmanship, they trash talk? No need to be shy, even those country-club Ryder Cup golfers get in each other's faces.
But no, these women enjoy each other's company!
"It's so much fun laughing and joking in the ready room," says Franklin. "It's so much more comfortable if we can chat," says Seebohm. "I'd hate it if it was silent."
As McEnroe might have said, you cannot be serious.
Franklin and Seebohm are what Tiger and Phil are too wound up to ever be - Facebook friends. They do what Kobe and Shaq would never have done while butting egos - following each other on Instagram. "She met Taylor Swift," said Seebohm "and I was so jealous".
Obviously there's something cleansing in the water which accounts for this. Either way it's a relief. In a sporting world overwrought with war analogies, here is something simple and nice. In a hyped-up planet of inflated rivalries and excessive testosterone this is grown-up competition. Not every sport needs to be like swimming but it's nice that swimming isn't like every sport.
"Backstrokers are pretty good (at this friendship stuff)," laughs Seebohm in explanation. Since they're not face down in the water perhaps they see the big picture.
This is not boxing, nor even basketball, where physical dominance in a contact sport comes into play. This isn't even tennis where you can affect your rival directly, where Rafael Nadal's kicking cross-court forehand to Roger Federer's single-handed backhand unravelled the Swiss. Here you mostly wear headphones, look down the tunnel of your lane through goggles and churn the water. Here, says Franklin, "the only lane you control is your own".
Maybe one day when swimming turns rich, when it finds its professional feet, when marketing folk tell them they need to build storylines and invent tales of how Franklin called Seebohm a "coward" - as Ayrton Senna said about Alain Prost - maybe then it will change. For now it's just natural and charming to see two rivals smiling and not swearing at the mention of the other's name.
Unlike tennis players who collide in corridors every second week and joust on court frequently (Federer v Djokovic already six times this year), Seebohm estimates she races Franklin "once or twice a year". The next time they meet after Singapore could be in Rio and they'll be toned, ready, focused, ambitious, driven.
Between them they've won 26 long-course world championship medals and you don't get there by smiling sweetly and invoking the name of Mother Teresa.
"We both want to win," says Seebohm, for neither understandably is without ego. "But if I come second (to her) it's still great. My friend won. You feel a little better."
Actually, regardless of who wins, they are already doing what champions are supposed to: which is to make sport look better.