There is something entirely random about the men's Olympic football tournament.

With clubs under no obligation to release their players, it is hardly a test of who is best at youth level -- men's football at the Games is usually an under-23 competition with three over age players, this time it is under-24 because of the year's delay. Instead, so much comes down to whether or not the teams are able to call on the services of their best eligible players.

There is certainly food for thought about whether the competition is worthwhile, but there is no doubt that Saturday's final is thoroughly worthwhile. It is not only a meeting of two attractive teams, but Brazil vs. Spain has also become a battle of ideas, a keen contemporary rivalry with -- certainly on the Brazilian side -- plenty of needle in there.

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Nearly a decade ago, at the end of 2011, Pep Guardiola's Barcelona met Santos in the final of the Club World Cup. To the astonishment of many Brazilians, Barcelona cruised to a 4-0 win of breathtaking ease. In the post match press conference, Guardiola stuck in the stiletto. His team treated the ball, he said, the way that his grandfather told him that Brazil used to do.

It is hardly surprising that this provoked a reaction. With their patient passing game, Spain at that time were reigning world and European champions, a few months away from successfully defending their continental title. But it was not just their triumphs that were putting Brazilian backs up. It was the swagger with which this was being achieved. Brazilians are understandably and rightly proud of being the only five-time world champions. But there was also pride in being seen as the spiritual guardians of what abroad is referred to as "the beautiful game," and in Brazil goes by the name of "football-art."

But with many Brazilian coaches now fixated with the counter-attack, here came the Spanish with pretensions to usurp them -- to win and then crow afterwards about the way they had done it.

True, many Brazilians were a little bored by the Spanish possession game. Where Barcelona had Lionel Messi to provide the individual fantasy and the mazy, destructive dribbles, in his absence Spain's passing could at times be stale. But at others it could be dazzling, a constant and dynamic exercise in geometry, new triangles constantly forming as two players exchanged passes and a third moved into position to receive.

But some Brazilians affected to see no beauty in this. During the recent Euros there were pundits on Brazilian TV wholly unable to conceal their desire to see the Spanish defeated, punished for the supposed arrogance of their faith in a passing game.

Two Spanish coaches have recently worked in the domestic Brazilian game, both advocates of a possession based style. Former Guardiola assistant Domenec Torrent was in charge of Rio giants Flamengo, while further south Internacional went with Miguel Angel Ramirez, fresh from an outstanding spell with Independiente del Valle in Ecuador.

Neither lasted long. Neither was given much time to build. Both felt the hostility of an environment in which many were willing them to fail, anxious to conclude that the Spanish possession game was not all it was being cracked up to be.

It is striking how few big games there have been between the two national teams in recent times. There was, of course, the final of the Confederations Cup in 2013. This effectively is the tournament where Spain's crown started to slip. They were irresistible for 45 minutes of a group game against Uruguay, and never as good again. When Brazil beat them 3-0 in the Maracana, it marked the end of the era of Spanish domination -- but it did not mark the beginning of a new Brazilian era. In both subsequent World Cups, just as in the previous two, Brazil's campaign came to an end as soon as they met a Western European side in the knock out rounds. And it is this that helps add extra spice to Saturday's Olympic final.

There is, of course, a gold medal at stake. But the game is also a pointer towards Qatar 2022. It pits a promising Brazil team into a challenge which is not entirely unrelated to the one the senior side will face at the end of next year.

Where the other European teams -- like the Germany side that Brazil met in their opening game -- have been weak, Spain are strong. Much of this has to do with the calendar. The Spanish season starts relatively late, meaning that the clubs have been more willing to release players and Spain have brought a squad with some of the young lions from the Euros where, in the semifinal, they were clearly the better side than eventual champions Italy.

Unlike Mexico, who were so disappointingly cautious against Brazil on Tuesday, Spain will come out to play, to have the ball, to work their triangles, to ask questions of the Brazil defence. Do they need too many chances to score a goal? Will they get many chances against a Brazil defence which has only conceded three goals in five matches? And at the other end, can they hold the Brazil attack in open space?

The doubt is especially pertinent if centre-forward Matheus Cunha is fit to return, since his versatility and back to goal play opens up attacking options which were not present in the goalless draw against the Mexicans. Richarlison is the top scorer, but Cunha is the only one on target in the knockout games. All across the attacking line, Brazil might relish a rare chance to launch counter-attacks against an opponent whose game-plan will not be constructed around caution.

The prospect is of a better final than the Olympic tournament probably deserves. And of a game whose ripples will be felt all the way in Qatar 2022.