Demonstration of the collusion risk mitigation effect of random tie-breaking and dynamic scheduling

We study the “groups of three” tournament format which was planned to be implemented in the 2026 FIFA World Cup. Finally, FIFA resigned from the format because its implementation is highly likely to lead to collusion (match-fixing). In our paper, we show that some modifications to this format may significantly reduce the risk of collusion. Such a reduction can be achieved by the following two innovative changes: random tie-breaking based on the goal-difference along with dynamic scheduling. Our Monte Carlo simulations show that the expected number of matches with high risk of collusion is reduced from 5.5 in the FIFA's initial proposal to 0.26 in our proposed design.