It is the first time since 1951 that The Open has been held in Northern Ireland and organisers expected a big demand for tickets, but nothing like this.

They have already had to warn fans about rogue ticket-sellers online.

If selling out a golf tournament nearly a year early is a remarkable feat, there have been plenty more on a similar theme in the past couple of years - in football, rugby union, cricket, tennis and hockey, all of them enjoying an upturn in spectator numbers.

Last February, when Tottenham played Arsenal at their temporary Wembley Stadium home, the crowd of 83,222 was the highest in Premier League history - just 38 spectators short of the all-time high for a league game in England, at Manchester City v Arsenal 70 years ago.

Wembley's extra capacity helped, of course, but it was not a freak occurrence: by last season's end the average attendance at all matches across English football's four divisions exceeded 16,000 for the first time since 1960, and second-tier crowds were the highest since 1954 - 20,489.

The boom goes a long way down, with 37 clubs in the fifth to eighth levels of English non-league football attracting more than 1,000 to home games last season.

In Scotland, Celtic and Rangers have had full houses at preliminary European ties this summer despite having already won the away leg.

There was even a record turnout on day one of the new football season in Northern Ireland on August 7.

Last year Paul Barber, the forward-thinking chief executive of Premier League club Brighton & Hove Albion, said: "We have created a new generation of football supporters."

Barber, who worked in North America with Vancouver Whitecaps, is annoyed by fans who "dismiss modern football" and said they were treated better than ever now.

"The past was a hell of a lot worse," he said.

Modern stadiums, better entertainment, and improved community work and fan engagement by many clubs have all helped.

"Things combine over a generation and we have created something people admire the world over," said Barber.

But football cannot do all the crowing, as a 2017 study by UEFA, the sport's governing body in Europe, showed.

The best supported competition in global sport on a match-by-match basis, that study showed, was not the NFL as many might have predicted, but rugby union's Six Nations Championship with an average of 72,000 - boosted by huge turnouts in London and Cardiff.

More than 26,000, a club record, watched Bristol play Bath yesterday in the Gallagher Premiership, which has the best supported rugby club in Europe in Leicester Tigers.

What of cricket, and the slow death of the five-day Test game that is so often written about, not just in Britain?

Test-match crowds in England are up by 46 per cent since the 1970s - not surprising given the level of entertainment in the current England-India series.

A report in the Guardian said: "Test match cricket has never been so popular…partly because the grounds have been redeveloped and are so much bigger now but also because, despite what our misty eyes tell us, the crowds were so much smaller back in the days everyone's now so nostalgic about."

This summer, huge crowds watched the revamped and excellently organised pre-Wimbledon tennis tournament at Eastbourne, and tickets are already going well for next year.

There was glowing praise for fans (120,000 of them) and hosts of the Women's Hockey World Cup in London in July and August, from the sport's governing body.

As the social historian Derek Birley wrote in Land of Sport and Glory, once sport had become properly organised (and overtaken public hangings as the big draw for spectators) in the latter part of the 19th century "people of all classes saw the sporting spirit as a vital ingredient in the British make-up".

The total turn-out for the biggest leagues and international matches in Britain's top sports, football, rugby union, cricket and rugby league, was around 43 million last season.

That number is dwarfed by the United States' figure of more than 150 million for its big five of Major League Baseball - by far the biggest draw in total because of the number of games played - American football (NFL), basketball (NBA), ice hockey (NHL) and football (MLS).

They also have big crowds at golf, tennis and other sports in the US - but so does Britain.

There are five Americans to every Briton and the US has nowhere near five times as many sport spectators.

German football, Indian cricket, Australian Rules Football and countless other popular local sports boost the numbers in a host of countries, but can anybody seriously claim to have diehard fans, across all levels of society, and in such a range of sports, as Britain has now?

Part of the reason for the boom in spectator numbers is the entertainment value, and the success of British sportsmen and women.

In football England reached the World Cup semi-finals and the Premier League is one of the most exciting competitions in any sport; in cricket England are rated well clear at the top of the one-day rankings; in rugby union Scotland are improving and England are third favourites for next year's World Cup in Japan; the Tour de France winner is Welsh - after years of English success; one of the world's top tennis players is Scottish; there are countless top British performers in motor racing, athletics, swimming, golf, boxing and other sports; and Ryan Moore is rated by many the best jockey since Lester Piggott.

There is a widely held view that the golden age of British sport was in the 1950s, when tens of thousands of people turned out at speedway and greyhound racing as well as the established sports. 

Others hark back to the 1970s but you will generally find that nostalgia and personal memories play a large part in the decision, and that the golden age of sport was when the person defining it was 15 to 20 years old.

Which gives those born around the turn of the century something of an advantage in the future, because the golden age of British sport is not in the 1950s or 1970s, it is now.

The London 2012 Olympic Games, Glasgow 2014 Commonwealth Games, and 2015 Rugby World Cup, despite England’s early exit, were all huge successes, as next year’s Cricket World Cup in England and Wales will be.

Football leads the way in this golden age, and there has been talk over recent days of a joint bid for the 2030 centenary World Cup by England, Scotland and Wales.

That makes perfect sense and if it happens you can be sure of one thing: it will be a sell-out.