Predicting the outcomes of annual sporting contests

Data from 20 sporting contests in which the same two teams compete regularly are studied. Strong and weak symmetry requirements for possible models are identified, and some simple models are proposed and fitted to the data. The need to compute the exact likelihood function and the presence of missing values make this non-trivial. Forecasting match outcomes by using the models can give a modest improvement over a naïve forecast. Significance tests for studying the effect of 'match covariates' such as playing at home or away or winning the toss are introduced, and the effect of these covariates is in general found to be quite large. Copyright 2006 Royal Statistical Society.