There is an immutable law concerning attendance at a sports event. It states that when two or more people sit down together to watch a match, one must immediately get up to go to buy food and drink, and extortionate prices be damned.

Bowing to this principle, the Australian Open this year for the first time allowed fans to move in and out of stadiums between games and not just at change of ends. Perhaps strategically, perhaps timidly, they did not announce this to the players, at least some of whom were taken by unpleasant surprise. To their credit, most adapted quickly.

The Australian Open has broken its record attendance.Credit: Chris Hopkins

They should not have been surprised. This is the nexus at which the whole show operates. As the Open burgeons, it becomes more and more for the fans than it is about the tennis.

The Open doesn’t even pretend otherwise. But wait (in a queue), there’s more. It sells around 40 per cent more tickets than there are available stadium seats on a given day. It proudly announces attendance records – and this year artlessly gilded those numbers by adding in gate figures from the week before the Open, which is for qualifying and practice.

But many attend in the way some attend school: they’re there to widen their social circle, not their horizons. They even have their own classification now: eventists. They come, they eat, they drink, they promenade, they see, they’re seen and they might or might not watch a spot of tennis – if they can be bothered waiting for a game to end.

And they spend money, on victuals, souvenirs, apparel. Tournament director Craig Tiley is almost guilelessly open about this. Whatever brings in the people, it’s all cash in. Not even the fraud that goes by the name of dynamic pricing deters them (dynamic pricing is really scalping, but by authorities).

Jannik Sinner signs some Australian Open merchandise.Credit: Getty Images

At a certain level, the Open has always been one big trade fair anyway. No one bothers even to try to fudge that any more.

There’s no doubt that on a pleasant day or evening, it makes for a brilliant atmosphere. I believe the prescribed term is party atmosphere. It’s clear from Melbourne’s streets that the Open attracts more visitors for longer than the annual fumigation that is the Formula 1 grand prix.