  In the last round of the FIFA World Cup group stage, games for which the
outcome does not affect the selection of the qualified teams are played with
little enthusiasm. Furthermore, a team that has already qualified may take into
account other factors, such as the opponents it will face in the next stage of
the competition so that, depending on the results in the other groups and the
scheduling of the next stage, winning the game may not be in its best interest.
Even more critically, there may be situations in which a simple draw will
qualify both teams for the next stage of the competition. Any situation in
which the two opposing teams do not play competitively is detrimental to the
sport, and, above all, can lead to collusion and match-fixing opportunities. We
here develop a relatively general method of evaluating competitiveness and
apply it to the current format of the World Cup group stage. We then propose
changes to the current format in order to increase the stakes in the last round
of games of the group stage, making games more exciting to watch and, at the
same time, reducing any collusion opportunities. We appeal to the same method
to evaluate a "groups of 3" format which will be introduced in the 2026 World
Cup edition as well as a format similar to the one of the current Euro UEFA
Cup.
