Ranking in unfinished round-robin tournaments

Abstract

The pandemic of coronavirus disease 2019 (COVID-19) stopped almost all sports leagues around the world. Some of them never resumed: the German premier men's handball league was canceled on 21 April 2020; the Dutch top soccer league ended with immediate effect on 24 April 2020; and the French Prime Minister announced on 28 April 2020 that the 2019/20 sporting season is over in the country.Consequently, several organisers faced an unenviable dilemma: how to decide the final ranking in the 2019/20 season? Should all results be abandoned? Should the current standing be frozen? Should a reasonable subset of the matches be considered? Since the sports industry is a billion dollars business, the answer has huge financial consequences as promotion and relegation, qualification for international cups, and the allocation of broadcasting revenue all depend on the league ranking.