  FIFA World Cup is one of the most watched sporting event in the world and its
popularity continue to increase. While currently 32 teams participate in this
event, starting with 2026 the number of participants will increase to 48. As a
result, FIFA proposed a major format change, the groups of 4 teams will be
replaced by groups of 3 teams, with the first two teams to qualify to the
second round. In this paper, we discuss the possibility of matches with limited
importance (called non-competitive) for final group standing for both 4-team
and 3-team groups and we introduce our definitions of collusion and dead rubber
games. Next, we discuss scenarios in both 4-team and 3-team group formats that
lead to such matches. Finally, we make an analysis of all group stage matches
from last six World Cup editions (1998 to 2018), and we predict the most likely
number of collusions and dead rubber games for the new format of the World Cup.
During our analysis we consider a variation of the proposed 3-group format in
which the order of matches for each group is predetermined. Our analysis show
that this variation has the potential of reducing significantly the number of
both collusion and dead rubber matches thus becoming an interesting option to
be considered for adoption by FIFA. In conclusion, we recommend FIFA to
implement a predefined order of group matches prior to the drawing. The seeded
team should play the first match with the team that is second best (according
to the drawing time FIFA Coca-Cola rankings), as well as the second match from
the group.
