Once you’ve been to a certain number of football stadiums they begin to blur into each other, but something about the Westfalenstadion in Dortmund breaks through the jaded glaze. The Grand March from Verdi’s Aida is blasting out of the stadium speakers and I’m staring at the fluttering mass of black and yellow flags on the Südtribune, the largest terrace in Europe. It’s a bit like gazing into the crater of a volcano. On the field, the squads of Borussia Dortmund and Arsenal are getting warmed up to play each other in the Champions League.

In the Bürgermeister pub a few hundred metres from the ground I had told a friend that it was the first time I had come to this stadium, so it was a sort of pilgrimage for me. “It’s a pity you couldn’t come here for a league match,” he said. The Champions League games are all-seater, which reduces the 25,000 capacity of the Südtribune by more than half, and the people who usually stand and sing together are separated into different seats, which supposedly affects the atmosphere. “The biggest games are usually not the best games, if you know what I mean.”

I silently cursed him for tainting my pilgrimage but right now the Südtribune is putting on the sort of show that makes you wonder what it must be like when it’s really full. Away from that mass of flags and banners, there’s nothing fancy about this stadium, just simple, steep, straight slopes sweeping skywards on all sides. The grey seats focus attention on the masses of yellow-shirted fans. The playlist is cheesy and upbeat – Jump by Van Halen, Happy Birthday To Ya by Stevie Wonder, a massive helicopter rotor noise, You’ll Never Walk Alone.

Then comes the unofficial club anthem Dortmund, Unsere Stadt – Dortmund, Our City. It’s a syrupy rock-ballad of the type German football clubs go crazy for. The singer is apparently a mate of the manager, Jürgen Klopp. Thousands of fans sing along to words that are pitched somewhere between Everything I Do I Do It For You and Allentown.

Dortmund, our city,

Is known throughout the world,

because she has something,

that other cities don’t.

From here came the steel,

The coal and the beer!

The most honest people,

Come here from the Ruhr!

But the real reason,

That people love this town

Is called BVB, BVB 09!

Borussia Dortmund, you are our love

Borussia Dortmund, you and you alone

Borussia Dortmund, you’ve given us so much.

The match is about to kick off and the Dortmund fans are making a lot of noise, but the ones I spoke to earlier didn’t seem to fancy it. Dortmund are carrying a lot of injuries – Reus, Hummels, Piszczek, Blaszczykowski, Sahin, Kagawa, Gündogan as always. People were saying 1-1 would be a good result.

Maybe they should have remembered the corny yet perceptive words of Dortmund, Unsere Stadt: “A black-and-yellow sea of flags / the Südtribune quakes / the opponent feels the thunderbolt / when he experiences this power.”

It looks that way in the first minute when Kieran Gibbs starts toward a loose ball ahead of him, then changes his mind and pulls back. Arsenal start off on the back foot and retreat from there. Their players are being hustled and chased into mistakes. They can’t keep the ball for longer than a couple of seconds at a time. The game is all happening in their half. They’re groping for their usual passing rhythm but they can’t get any control. Just before half-time, Ciro Immobile runs through the middle and scores. Just after half-time, Pierre-Emerick Aubameyang runs through the middle and scores. Arsenal have been run off the park.

At the end, Dortmund’s players remain on the field and enact a ritualised celebration with the fans. They wait in the centre circle as the crowd serenades them from all corners, then they go down and dance in front of the Südtribune.

It’s quite a display considering this is only the first Champions League game of the season, but then again the bond between players and fans is what marketing professionals might call BVB’s USP.

More than a club

Dortmund is a quiet place. It’s not a pretty town. It’s not a big cultural centre like Munich, with gleaming spires and snow-capped Alpine peaks along the southern skyline. The only thing looming in Dortmund’s southern skyline is Signal Iduna Park. The team is the biggest thing in the town and when the team wins, it feels like everyone is involved.

Of course, German football fans really are involved with their teams in a different way from fans in, say, the United States or England. The difference is even embedded in the language.

If there is one feature of the ever-more familiar American sports culture that still seems slightly alien, it might be their way of referring to teams as “franchises”. There is something pathetic about describing world-famous sporting institutions like the Boston Red Sox or the Dallas Cowboys with a word that is more commonly associated with the local branch of McDonalds or Dunkin’ Donuts.

In Ireland and England, teams are usually referred to as “clubs”. In German, the word is “Verein”, which means something subtly different. A closer translation of “Verein” would be “union”. Where “club” has an overtone of exclusivity – think of golf clubs, private members’ clubs, club class – “Verein” implies inclusivity (the German word for “golf club” is . . . . “Golfclub”). Where the American “franchise” makes it pretty plain that the fans are customers, and the English “club” is something fans “follow” rather than something they’re members of, the people who pack the Westfalenstadion to watch Ballspielverein Borussia 09 are not merely fans, but members of a giant association.

The collective

“We really wanted to put a pressing machine on the pitch tonight,” Klopp says on TV. “I will remember this match because the football I love looks like this. I liked how ready we were, how energetic we were, how well we focused and how we fought. This was a game for my folder.”

From Klopp’s point of view, the most pleasing statistic is that Dortmund have collectively run 11km more than Arsenal. That, he has always maintained, is as good as having an extra man on the pitch. Outworking the opposition is the essence of Dortmund’s style.

Somebody asks a question about the number of times Dortmund forced Arsenal into mistakes in their own half. Klopp grins. Well, their half is the best place to win the ball. One pass, and you’re in on the goalkeeper.

His press conference over, Klopp bustles out of the room, stopping to chat to individual journalists along the way, oozing confidence, charisma and easy charm.

At that moment, nobody suspects that Dortmund are about to embark on a four-match winless run in the league, leaving them 10 points behind Bayern after only seven games. Their domestic title challenge is over before it ever really began.

Philosophy

With the youngest squad in any of the top five European leagues, Dortmund came from nowhere to win the league title in 2011, then won the domestic double in 2012 and reached the Champions League final in 2013. Klopp had convinced his players that together, they could beat the world. They shone with energy and idealism. The team and the city were living a beautiful dream.

Unfortunately, reality soon intruded in the shape of the super-rich European clubs who came to poach Dortmund’s best players. First Nuri Sahin joined Real Madrid. Then Shinji Kagawa joined Manchester United. Dortmund took those losses in their stride. But then Mario Götze joined Bayern Munich. Six months later, Robert Lewandowski signed a pre-contract to join Götze in Bavaria.

Sahin and Kagawa failed abroad and both of them have since boomeranged back to Dortmund – a testament to how valuable Klopp made them feel. The losses of Götze and Lewandowski to their biggest rivals have been harder to cope with. No club can lose players of that quality and keep going as though nothing happened.

The haemorrhage of the best players has a debilitating effect beyond the immediate weakening of the first XI, because everyone assumes that the remaining stars will soon follow.

The big German players still at Dortmund are Mats Hummels and Marco Reus. Hummels, who actually came through the youth system at Bayern before joining Dortmund aged 20, has said the sort of things the fans want to hear. “We earn enough here in Dortmund,” he said in an interview last week. “There will always be someone who can pay more than BVB but Dortmund have made a lot of progress during my time here. In any case, I believe it’s enough for me. We still have so much further to go here.”

Reus has said the same sort of things in the past but there are too many rumours linking him with moves abroad to assume that his commitment is rock-solid. He has the same agent as Götze and Toni Kroos, who left Bayern for Real Madrid in the summer. Reus will be 26 at the end of this season and if he is ever going to make a move to a superclub, next summer looks like the best opportunity to do so.

In the long run, the only way Dortmund can hold on to the best players is by matching the money they can make elsewhere. Right now they earn €7 million a year from their kit manufacturer, Puma. Manchester United’s deal with Adidas is worth 10 times as much. Dortmund therefore have a lot of ground to make up. Signs of the transformation that is under way can be seen at the stadium, where they have build a new addition to the north stand: “BVB Fan-Welt”, a huge merchandising outlet selling all kinds of tat emblazoned with the club slogan “Echte Liebe” – True Love.

Dortmund’s marketing is clever - before the German cup final in Berlin last May, black and yellow posters appeared all over town with cutesy slogans aiming to butter up the Berliners. “Hey Berlin – great to see you again! sorry about all the noise!” and that sort of thing.

Marketing is still marketing, however, and there is a price to be paid for selling yourself. BVB prides itself on being an authentic symbol of its community, but it must become a voracious corporate monster in order to compete with Bayern and the other rich European clubs. In the Bürgermeister before the Arsenal game, fans were sniggering at the club’s announcement that they were raising equity from a share issue to various corporate partners, suggesting “Kapitalorientierte Liebe” – Capital-Oriented Love – as a possible new slogan.

Will the metamorphosis be worth it? Maybe the uncertainty about what the club will be like in the future fuels the sense of nostalgia for the very recent past. One fan who has been going for nearly 25 years told me he believed that even if they win the title again, it can’t possibly be as good as the title wins in 2011 and 2012. That team was Dortmund’s answer to the Lisbon Lions. Even if Bayern can be stopped snatching their best players away, these fans aren’t quite greedy enough to believe they’ll see more than one team like that in their lifetime.