"Having talent is one thing," the Borussia Dortmund coach Jurgen Klopp said recently. "But much more important is what you do with it. And in this regard we have been well on track for a couple of years now, I think."
There is no doubt. With average crowds above 80,000, Dortmund are the best-supported football club in the world. But they are not in the top 10 in annual revenues nor in achievements; they have one European Cup, in 1997. Yet they have thrilled football recently by playing a fast, attacking game and pressing to the extent that none of their team ever stay still.
Like Barcelona, they have the idea that, if they lose possession in attack, they do not retreat but stay up field and immediately win the ball back. Dortmund's players never stop running. Even their most immobile outfield player, the defender Felipe Santana, runs an average of 103 metres per minute. No other team works as hard as Dortmund.
They finished top of the toughest Uefa Champions League group, that containing Manchester City, Ajax and Real Madrid. Now they are on the brink of a second Champions League final after demolishing Real 4-1 on Wednesday.
Dortmund fans knew they had a good team; they had seen them win the Bundesliga twice in succession, with last year's triumph part of a domestic double. But they did not expect this. Just playing Madrid again was a bonus after being seconds from elimination by Malaga in the last eight.
The Bundesliga crown has gone to Bayern this season, but a buzz surrounds Dortmund, Europe's hottest club. They have a young team: their average age in this season's victory over Manchester City was 24, and that figure was inflated by their veteran goalkeeper Roman Weidenfeller, 32, their only player over 27. And many of them are home-grown.
Nine players who saw action when they beat City in Manchester in September held German passports and just one, Marco Reus, the German Footballer of the Year, cost more than €4 million (Dh 19.1m).
Dortmund do much right. Season tickets to stand on the giant Sud-tribune, football's biggest standing terrace, with 25,000 capacity, can cost as little as €200. The noise created is known as the yellow wall and can intimidate opponents. A fan might well make a lot of noise watching players like Wednesday's four-goal hero Robert Lewandowski, the midfielders Mario Goetze and Reus, the centre-back Mats Hummels and Lukasz Piszczek, an attacking right back, and one of three Polish players in the team alongside Lewandowksi and the midfielder Jakub Blaszczykowski.
Not eventhe announcement of Gotze's impending German-record transfer to rivals Bayern Munich could spoil Wednesday's party. They are also likely to lose Lewandowksi to a richer club, just as they lost Shinji Kagawa in 2012 and Nuri Sahin a year before.
Yet despite selling their best players, Dortmund come back stronger, with Klopp credited as the master motivator and communicator. "Playing for Dortmund is a lot of fun," Reus said. "It's a loose, casual club." Fun and casual are not words used to describe other German clubs.
That attraction is why Dortmund will not be devastated about losing two more of their best players. They would prefer Lewandowksi and Goetze stayed, but the green shoots of recovery are almost instant at Dortmund, a club which nearly went bankrupt in 2005. That would have meant an automatic demotion to amateur football.
The lesson learnt was that while Dortmund would always aspire to success, never again would they go into debt for it, as they had done. With no money, they had to try something new and hit on a winning formula of developing their own players or finding cheap, hungry, emerging talents who never stopped running.
And they have Klopp and a stable background staff to hone and improve those talents.
"Dortmund are rolling onwards like a steamroller," said Arsene Wenger, the Arsenal coach. "When a team of such class plays this well, they will be very hard to stop."
Madrid tried and failed. They will try again on Tuesday in the Bernabeu.