Basically the group stage is the series leading up to the REAL playoffs.

The quarter-finale (8 teams), half-finale (4 teams) and finale (the final two).

This makes sure that the one day flies aren't the ones competing against each other. They've already proven themselves in the groups.

Each match in the group is good for 3, (a win) 1 (a tie) or 0 (a lose) points for each team.

At the end of the 3 matches that each team plays in the group the 2 teams with the most points in the group go on to the quarter finals.

If two teams have an equal amount of points then the amount of goals scored during the matches also comes into play to decide the group winners.