Revisiting the draft: A revised probability based approach for allocating draft selections in Australian rules football

The existing method of allocating draft selections in the AFL is based on inverse ladder position at season¿s end. A criticism levelled at this system is that it provides teams who are unlikely to figure in the finals with an incentive to lose, with greater rewards being provided to teams who win fewer matches. In 2006, we proposed a probability-based system that allocates a score when a team wins an `unimportant¿ match. Calculation of unimportance was based on the likelihood of a team making the final eight following each round of the season. A limitation of this model was that higher picks were awarded to teams who won a string of matches late in the season and just missed out of playing in the finals. Furthermore, teams who won very few matches and finished in the bottom ladder positions were awarded few draft allocation points, and thus were unlikely to receive high draft selections. In this paper, further refinement of the original model is undertaken to address these shortcomings. Draft point allocations are moderated based on the quality of opposition being played and the number of matches the team has won during the season to date. Using this revised approach, we simulated 100,000 seasons based on actual season data for the 2009 AFL home-and-away season. We investigate the distribution of draft picks awarded to each ladder position, and highlight teams who are more or less likely to be awarded top draft picks under the revised system.