Copa America final the biggest game of Jorge Sampaoli's impressive career
Either Chile will finally have something to put in their trophy cabinet, or Argentina will have ended a 22-year wait for a senior title. There is plenty at stake in the Copa America final, but for one man, the question is even more important.
Chile will probably have other chances to win something in the future; Argentina surely will have. But for Chile coach Jorge Sampaoli, this is the match, the one that he has spent his entire professional life preparing for and imagining.
The little man is a show apart while his side are in action, marching up and down his technical area as if he ran on batteries. It is the outward manifestation of an inner force that has carried him a long way.
Sampaoli comes from Casilda, a small town some 35 miles outside Rosario, Argentina's second city. The local press often still refer to him as "el casildense," as if his humble origins can never be forgotten. An injury wrecked his dreams of a career as a player and so, working his way up, passing through clubs in Peru and Ecuador, he is now acknowledged as one of the most interesting coaches around.
As well as the force of his personality, Sampaoli carries with him the power of an idea. Here, he is the first to pay tribute to his idol and predecessor as Chile coach, Marcelo Bielsa. Sampaoli's aim is always to attack and grasp the game by the scruff of the neck, to pressure the opponent in their half of the field, to attack quickly down the flanks, to throw men forward at pace -- all tactics taken from the Bielsa playbook.
It is a method of play that requires the swagger and confidence that an opponent with far more individual talent can be out-attacked and beaten. And now comes his philosophy's big test. In terms of individual attacking talent, the bar could not be set much higher. Argentina will field Lionel Messi, Sergio Aguero, Angel Di Maria, Javier Pastore and still have plenty of firepower on the bench. It is the little man from Casilda against the giant.
This is the first time Sampaoli has been in charge of Chile in a match against the land of his birth. His adopted country have only ever beaten Argentina in one fully competitive match, a World Cup qualifier in October 2008 during Bielsa's reign. Can Sampaoli emulate his idol and mastermind his team to a win that, with a title at stake, would be even more glorious?
Argentina know what to expect. "There are footballing ideas that don't change," says coach Gerardo Martino. "Whoever they are against, Chile are going to play the same way. They are going to attack us as they do against any opponent, and they are going to do it with a lot of men."
Indeed, Chile's idea remains the same, but the way it is executed goes through frequent alterations. In the current tournament, for example, Chile have used five different starting lineups in their games, which now looks set to be six in six.
Under Sampaoli, Chile have alternated between two base formations. Against weaker opponents they tend to line up in a back four, though it's something of a misnomer because a key part of the system is the idea that both full-backs can push forward simultaneously. It would perhaps be more accurate to argue that, in conditions of technical superiority, they have only two out-and-out defenders.
Against stronger opponents, they protect themselves a little better. Sampaoli always wants his wide defenders to attack, and so extra protection is provided with the inclusion of a third centre-back.
So far in this tournament, Chile have had a relatively easy ride. In the past three games, against Bolivia, Uruguay and Peru, Sampaoli has lined up a back four. But in the game against Argentina, with that breathtaking collection of attacking stars, the situation demands a little more caution. This is especially true given the absence through suspension of Gonzalo Jara, Chile's quickest defender, and Sampaoli's own doubts about the left side of his defence.
The coach cannot seem to make up his mind between Eugenio Mena, Miiko Albornoz or Jean Beausejour on the flank from which Lionel Messi likes to work his tricks. The probability is that Francisco Silva will come into the back three in place of Jose Rojas, who looked uncomfortable replacing Jara against Peru, and that either Mena or Albornoz will play to his left, with Mena or Beausejour at wing-back.
Essentially this means that an extra defender has been brought into the team, which of course means that a more constructive player will have to drop out. The speculation in Chile is that despite his fine performances so far, that someone will be Jorge Valdivia.
The twinkle-toed playmaker is the enfant terrible of Chilean football, consistently promising more than he delivers -- until now. At 31, Valdivia is aware that this is his moment. Fitter than ever before, he has lasted the pace of the games and has kept finding the solutions to unlock packed defences.
But does Sampaoli trust him against Argentina? Does the coach think that Valdivia can get the better of a duel with Javier Mascherano?
In the last World Cup, Valdivia played (and scored) in Chile's opening game when they beat Australia, with a back four. For the subsequent matches against Spain, Holland and Brazil, Chile introduced the extra defender, played three at the back, and Valdivia was on the bench, coming on late in the first two games and, cutting a highly frustrated figure, sitting out the decisive second-round clash against Brazil.
Valdivia does not usually start when the team play three at the back. An exception was the second match in the current tournament against Mexico. Sampaoli said before that game that he wanted his defenders to be able to play one against one with the opposing strikers. But it was a plan he was very soon forced to abandon. Three at the back, two wide and two up front left a lot of space for the three midfielders to cover.
With Valdivia as part of the midfield block, the defence was left exposed, and well before half-time, Sampaoli shuffled his cards and reverted to a back four. So if he could not play Valdivia with a back three against Mexico's second-string side, what chance does he have against Argentina?
The absence of Valdivia would presumably shift Arturo Vidal in the central position behind strikers Alexis Sanchez and Eduardo Vargas. Sampaoli will be optimistic that his front pair (especially Sanchez) can get at Argentina down the flanks, where they have looked vulnerable throughout the tournament.
He will also have paid plenty of attention to the goal Argentina conceded against Paraguay in the semifinal. Martino's side try to play out from the back, which, for a while at least, was made difficult by Paraguayan pressing, whose finest moment was with a ball won in the Argentine half and lashed home by Lucas Barrios.
Chile will back themselves to press better and for longer than Paraguay, which means that there will be a lot of responsibility on Vidal and Charles Aranguiz to interrupt the Argentina attacks at the source. Failure to do so could leave that Chilean defence very open to Argentina's individual talent, a thought that may well have entered Jorge Sampaoli's nightmares as he prepares for his big day.
Tim Vickery covers South American football for ESPN FC. Follow him on Twitter @Tim_Vickery.