AbstractSexual selection, whether mediated by male-male competition, female choice, or male choice, is often realized through a series of pairwise contests. Experimental evolutionists have long applied male-choice and female-choice experiments to quantify the relative mating abilities of genotypes, an important component of fitness. Here, we consider Drosophila mate-choice experiments and apply two mathematical models, the Bradley-Terry and the Élő models, which have been explicitly designed to quantify the merits of contestants and establish a ranking based on results from pairwise contests. Methods such as the Bradley-Terry model and Élő ratings also provide a way to predict the outcome of contests that have not yet taken place. Leave-one-out validation approaches allow us to assess the utility of these models to quantify relative fitnesses, how well the models fit the data, and how well they perform at prediction. After applying these methods to Drosophila mate-choice experiments, we interpret the results in terms of sexual selection, and discuss the implications of departures of the data from good fits to the models.