Impact of established clubs on probability of survival in top leagues

Abstract

Football leagues across the world apply the European promotion-relegation model, where the best teams in the highest-ranking minor league are promoted to the major league from which the worst teams are relegated to the former. This paper proposes a simple statistical model that calculates the probability of non-established clubs avoiding relegation, by assuming the existence of a cohort of established clubs, which rarely if ever are relegated. It uses three data items (i.e. total number of clubs, number of established clubs and number of clubs relegated). It is the number of established clubs which is critical, rather than which clubs should be so categorised. For illustrative purposes the model was applied to the English Football Premier League (EFPL) for its first twenty-one seasons. It was found that the means of the model and the observed distributions for the key EFPL cohorts of seven and eleven established clubs were not significantly different statistically, suggesting that the model reasonably reflects the observed distribution for each size of established group. Also, the probability of a (non-established) club surviving eight seasons, assuming no established clubs, was 600% greater than if there were a cohort of eleven established EFPL clubs. This demonstrates that the projected probability of survival will be greatly overestimated unless a cohort of established clubs is assumed. Any football club in such a major league, particularly one that is newly promoted, can use this statistical model to calculate the probability of avoiding relegation and thereby generate a more sensitive assessment of risk