  According to previous studies, competitive balance has significantly declined
in the UEFA Champions League group stage over the recent decades. Our paper
introduces six alternative indices for measuring ex ante and ex post
competitive balance in order to explore the robustness of these results. The ex
ante measures are based on Elo ratings, while the ex post measures compare the
group ranking to reasonable benchmarks. We find no evidence of any trend in the
competitive balance of the UEFA Champions League group stage between the
2003/04 and 2023/24 seasons.
