“Choose your opponent”: A new knockout design for hybrid tournaments†

Abstract

We present a new, simple knockout format for sports tournaments, that we call “Choose Your Opponent”, where the teams that have performed best during a preliminary group stage can choose their opponents during the subsequent knockout stage. The main benefit of this format is that it essentially solves a recently identified incentive compatibility problem when more than one teams from a group advance to the knockout stage, by effectively canceling the risk of tanking. This new design also makes the group stage more exciting, by giving teams a strong incentive to perform at their best level, and more fair, by limiting the risk of collusion and making sure that the best group winners are fairly rewarded in the knockout round. The choosing procedure would add a new, exciting strategic component to the competition. Advancing teams would choose their opponent during new, much anticipated TV shows which would attract a lot of media attention. We illustrate how this new format would work for the round of 16 of the UEFA Champions League, the most popular soccer club competition in the world.

UEFA Against the Champions? An Evaluation of the Recent Reform of the Champions League Qualification

“…Csató (2020) investigates the effect of this seeding reform from a theoretical point of view. Guyon (2021a) proposes a new knockout format for the Champions League through the policy of "choose your opponent".…”

Football Group Draw Probabilities and Corrections

“…Others propose completely new draw mechanisms, e.g. [12]. The paper [16] even briefly postulates a possible Markov chain procedure (specifically an exclusive Gibbs sampler)…”

Dynamic Programming Algorithms for Computing Optimal Knockout Tournaments

“…There is also interest in the literature in designing new formats of knockout tournaments. For example, a new format based on actively involving the teams in defining the tournament format, was recently proposed in [13] for the specific competition of UEFA Champions League. The proposed format was coined "Choose your opponent" with the claimed benefit to make group stages more exciting.…”