Abstract
This study examines the effectiveness of successive rules changes on competitive balance, as measured by score differential in a match, over the history of seven European professional soccer leagues. Poisson regression results show that various rules changes do have an effect on match competitiveness in European professional soccer.
Acknowledgements
The authors are grateful to two anonymous referees and David Peel for helpful comments and to Ruud Koning for providing the data used in this study. The usual caveat applies.
Notes
1 For a history of IFAB and the history of the rules of soccer, see www.fifa.com/classicfootball/history/law/ifab.html and the links provided thereon.
2 For more on the FA, see www.thefa.com/.
3 See Szymanski (Citation2003) for more on the common traits in European professional soccer and common sports elements that follow the soccer system.
4 For a timeline of historic events in soccer, see http://www.timetoast.com/timelines/soccer-history-2.
5 The use of the absolute value of the goal differential provides an alternative empirical approach to measure competitive balance. Previous studies have used the SD of winning percentage (e.g. Szymanski, Citation2003), the SD of winning percentage relative to an ideal SD (e.g. Vrooman, Citation1995), the Gini coefficient (e.g. Quirk and Fort, Citation1992) and the Herfindahl–Hirschman index (e.g. Depken, Citation2002).