This paper aims to explore at what league size competitive balance reaches its best level through a longitudinal study and by using the English Premier League (EPL) as an example.
To test the influence of league size on competitive balance in the EPL, the authors first calculated competitive balance scores for 22 seasons between 1995/96 and 2016/17 under the existing 20 team system. They then calculated a further ten normalised competitive balance scores for each EPL season by adjusting the league size to examine the league size threshold at which competitive balance in each season of the EPL was at its best level.
The analysis indicates that the current league structure of 20 teams compromises the overall level of competitive balance in the EPL in comparison with a league comprising between 10 and 19 teams. However, the authors cannot pinpoint the precise league size at which the EPL is most competitively balanced, as no significant differences were observed between the competitive balance indices for these league sizes.
The findings of this study have practical relevance for league organisers and the Union of European Football Associations given that they themselves have stated that competitive balance will be a big challenge for the European football industry in the coming years.
