Measuring Competitive Balance in NHRA Pro Stock Motorcycle

Competitive balance is important to all sanctioning bodies of sport. While league based sports can make use of salary caps and drafts to enhance competitive balance among teams, changes to the rules package are implemented to... [ view full abstract ]

Competitive balance is important to all sanctioning bodies of sport. While league based sports can make use of salary caps and drafts to enhance competitive balance among teams, changes to the rules package are implemented to enhance competitive balance in individual sports. The National Hot Rod Association (NHRA) is the largest motorsports sanctioning body in the world. Among its four professional classes is Pro Stock Motorcycle. This study examined the competitive balance effects of changes to the rules package in the NHRA’s Pro Stock Motorcycle category for the 2011 through 2013 seasons, in two ways: within season competitive balance and between season competitive balance. This study uses the Adjusted Churn index to examine the within season competitiveness. Between season competitiveness is analyzed using the Lorenz curve and accompanying Gini coefficient for both points and purse. We also investigated the number of competitors participating each season for each event. Our results indicate the changes to the rules package for NHRA Pro Stock Motorcycle for the 2013 season had significant positive effects on competitive balance, but did not have a positive effect on increasing the number of professional competitors. For each measure of competitive balance, we developed a corresponding nonparametric measure of reliability so that the sanctioning body and track managers can better predict, with confidence, the level of competitive balance in a subsequent season, given the current rules package.