The World Cup is international soccer's biggest, most prestigious competition. It runs every four years, and features the top teams and players from around the world, all competing for the title of world champion.
Though the World Cup finals begin today, hosted this year by Brazil, the World Cup has actually been going on for years now.
The June 12-July 13 tournament is the culmination of rigorous qualifying tournaments that took place in each continent over the course of the past three years.
Each of the world’s nations had a shot. Many fought dearly. But only 32 teams made it to Brazil to compete in the finals.
FIFA uses a system to create eight groups that are designed to be both geographically balanced and filled with roughly equally strong groups.
For example, Group A is made up of Brazil, Croatia, Mexico, and Cameroon. Group B: Spain, the Netherlands, Chile, and Australia.
The eight Groups of four teams will compete in the first two weeks of the Cup, with each team playing the other three members of its group once in a “round robin” mini-tournament.
The two best teams from each group advance to the second round, at which point the tournament is a single elimination bracket for the top 16 teams, similar to college basketball’s Sweet 16 or any major tennis tournament. If you lose, you go home.
How exactly will the group stage be settled?
Well, if you win a game, you are awarded three points. If you tie, you get one point. If you lose, you get zero points. The two teams with the most points from each group advance.
If two teams have the same number of points at the end of the group stage, then goal differential will be taken into account. If a team scored four goals in their three first-round games, but gave up 2 goals, its goal differential is +2. The team with the better goal differential will advance. If the goal differential is the same, then the team that scored the most goals advances.
If goal differential is the same, the victor in any head-to-head results between the tied teams advances. And in the very rare event that both teams are equal on all tie-breaking criteria, FIFA will draw lots to determine a winner. (Such a coin flip has only happened once, in 1990, to determine seeding in the elimination bracket: neither Ireland nor the Netherlands, who were tied on points and goals, was eliminated.)
[Editor's note: The original version of this article ran on June 11, 2010.]