Predicting Qualification Thresholds in UEFA's incomplete round-robin tournaments via a Dixon and Coles Model

Abstract: In the 2024/25 season, UEFA introduced the incomplete round-robin format in the Champions League and Europa League, replacing the traditional group stage with a single league phase table of all 36 teams. Now, the top eight qualify directly for the round of 16, while teams ranked 9th-24th enter a play-off round. Existing simulation-based analyses, such as those by Opta, provide guidance on points presumably needed for qualification but show discrepancies when compared to actual outcomes in the first season. We address this gap using a bivariate Dixon and Coles model to address lower draw frequencies, with team strengths proxied by Elo ratings. This framework allows us to simulate matches and derive qualification thresholds for direct and play-off advancement. Our results offer scientific guidance for clubs and managers, improving strategic decision-making under the new UEFA club competition formats.