An Extreme‐Value Model for Predicting the Results of Horse Races

SUMMARY Results of horse races in 1979–80 are analysed to see if the extreme‐value distribution can model the times to run horse races: horses with the same bookmakers' odds of winning are classed as one group; the distribution of times for each group is extreme‐value with location parameter β depending on the win odds; and the scale parameter 8 is common to all groups. The model predicts that the win probability p for the group is p = exp ((β 0 – β)/θ) for some constant β 0 , and this is borne out by the data. Only the tail of the empirical distribution functions is consistent with the model; however, it is essentially this tail which determines the win probabilities, so if the aim is to do just that the model will serve a useful purpose.