No wonder, then, that Mauricio Macri — once the president of Boca, and now the president of Argentina — declared before the first leg that “whoever loses will take 20 years to recover.” There are plenty of fans who might suggest that estimate is on the low side.

There are glimpses of how much it means everywhere in Buenos Aires, and throughout Argentina, too: Between them, River and Boca claim to be supported by around 65 percent of the country’s population. It is not just the sight of jerseys tied to balconies or hung from windows, the blue and yellow of Boca, the red and white of River. It is not just the sound of countless conversations in cafes and bars and restaurants, all of them discussing what might happen, who might win.

It is not just the headlines in the newspapers or the voices crackling through the radio, revealing that some 2,000 police officers will be on duty at the Monumental, River’s home stadium, on Saturday evening, or that prosecutors in Buenos Aires have opened an investigation into the illegal resale of tickets, with prices reportedly rising as high as $2,000, or more.

It is the individual stories, too. There is the one about Matías Alvarez, a law student who has not been able to find work but did manage to secure a ticket for the game; on Facebook, he wrote that he would not sell it for any sum in the world, but that he would trade it happily if someone could offer him a job “in some sort of office or business.” Some things, he said, were “more important.”

He was flooded with offers, people willing to offer employment just to be there, at the game; River eventually intervened to assure both him and his benefactor a place inside the stadium.

That one was picked up by the Argentine media, but there are countless others that remain anonymous: the fans making the journey home from New York and Toronto and Paris and Madrid, clad head to toe in River jerseys and T-shirts, simply because they had to be here; the fan who waited all evening outside Carlos Tevez’s house, where Boca’s players had gathered for a team-building barbecue, just to wish them all good luck; the taxi driver whose family removed his Boca shirt from his wardrobe so that he was not tempted to wear it as he ferried people to the stadium on Saturday.