There are some incredible factoids going into this Under-17 World Cup final. For example, that neither England nor Spain, football's traditional powerhouse and its new leader, has ever won this tournament. Or that England, who have an abysmal record at World Cups post 1966, are making up for lost time: this is their second World Cup final in five months, having won the Under-20 tournament in South Korea in June.
This tournament has traditionally been the preserve of African teams - Nigeria and Ghana have won seven of the 16 titles so far between them - and the cynical view is that the European teams have now started taking an interest in youth football. That is being disrespectful to both sides; European nations have long had strong academy structures, and African countries have had strong youth teams. As they did this time too, in Mali and Ghana.
Spain's coach Santi Denia was tactful today when asked about European dominance given the two finalists. There's no difference between European and African teams in terms of talent, he said, the difference is in how you handle the small details.
Or perhaps the really big details, which England coach Steve Cooper implied when he said the difference lies in focus. St George's Park, where the national academy is housed, was set up in 2012 and the two FIFA finals this year can clearly be linked to that. To appreciate English football's focus on youth, you can look at history: Manchester United have had a graduate from their youth team in every matchday squad for exactly 80 years. That's 3,882 consecutive games.
Or you could turn to the present, still in Manchester, where United's rivals City have built arguably the best, most modern youth training facility in football. It has produced four members of this England side, all of whom have played key roles in this tournament: captain Joel Latibeaudiere, goalkeeper Curtis Anderson, midfielder Phil Foden and Jadon Sancho, who, though he left midway to join his new club Borussia Dortmund, is very much a City product.
It's no surprise that the Etihad project was conceived and executed by two former senior Barcelona officials, who used the template of La Masia, the Spanish club's famed and fabulously successful youth system. It was also the carrot to lure the third ex-Barca man: the jewel in the crown, Pep Guardiola.
That's just one example of how football is essentially a flat world, with styles and influences coming from across national borders (Barcelona's own tiki-taka is of course of Dutch origin). Another example is England coach Cooper, who said today how he was influenced by Spanish football while coaching at Liverpool. Rafa Benitez was the boss of the senior team, Xabi Alonso its beating heart, and the emphasis on technique spread through the club.
And so it comes down to 22 players, and their support cast, in Kolkata. There's shared history, and there's also previous. The last time these two sides met, in the Euro Under-17 final in Croatia in May, penalties were needed to separate them. Two of England's heroes in this campaign - Latibeaudiere and top scorer Rhian Brewster - missed their kicks and Spain won the title.
Earlier today, Brazil's coach Carlos Amadeu - whose team faces Mali in the third-place playoff - was asked about adversity. His response was typically Brazilian: "Football is life - you fall and you have to pick yourself up. Only, in sport, you have to do it much quicker."
Well, Latibeaudiere is now captain and tomorrow will lead his team-mates out in a World Cup final. Brewster is the first player to score consecutive hat-tricks in the knock-out stages of this competition.
Spain's ride hasn't been all that smooth. They began this tournament with a loss to Brazil but they then won their next five games, including two tricky knockout ties against France and Mali.
This is, for both teams, the end of this particular rainbow, the end of a two-year journey of bonding and togetherness. Once the match is over, the players will go their different ways, into club systems, into professional careers, into the public glare.
For these teenagers, tomorrow is the final exam, the last day of school. There will be heroes, there will be tragedy, there might even be a villain or two.
But while there will be a winner, there won't be losers. The beauty of the Under-17 World Cup is that for these players, among them the world's best teenage footballers, this is the first day of the rest of their lives.