Competitive balance in a quasi-double knockout tournament

In 2001, the All-Ireland Gaelic Football competition changed from being a singleknockout tournament to a quasi-double knockout competition. Similar natural experiments in economics and operational research theory suggest such a change should reduce the competitive balance in the competition. Using a Hirschmann–Herfindahl Index measure of concentration and a bootstrapping approach, we confirm that the new structure leads to a less competitive outcome and, importantly, this outcome is less uncertain. Our bootstrapped results show that in the long run, with larger samples, there is less competitive balance in the new competition structure than in the older structure competition structure. Finally, we also consider a stochastic dominance approach to evaluating the change in tournament structure, but the low power due to the presence of ties in our small sample leads to an inconclusive outcome.