Modelling paired comparison data with large numbers of draws and large variability of draw percentages among players

A linear paired comparison model is proposed that allows a large number of draws and large variability of draw percentages among the players as is the case for chess or soccer matches. The model can also be extended to allow home ground advantage. When only summary results are available, maximum likelihood estimation is not feasible and we recommend a method based on matching the numbers of home wins, home draws, away wins and away draws for each team with their expected values. We also discuss the problem of obtaining estimated standard errors. As an illustration, the suggested model is fitted to the 1993-94 English Premier Soccer League results.