“How it works. The progress of the World Cup from match to match is determined from the beginning: there are no further draws to decide who plays whom in subsequent rounds. To maximise the spectacle, the competition is structured, broadly, to ensure that the “bigger” teams don’t face each other (and knock each other out) too early in the competition, and to ensure that all 48 teams have an incentive to field their strongest side for every fixture. The top two teams from each group automatically qualify to the next round. Because the winner of a group will face a second- or third-placed team from another group, the hope is that France, for instance, will not rest on their laurels once they have enough points to qualify for the knockouts but will try to win their last game to get what in principle are easier opponents in the next round, the last 32. …”
Guardian