Impact of Coach Changes on Performance of Football Clubs in Iranian Premier League

The purpose of the present study was to investigate the impact of coach changes on the performance of football clubs in the Iranian premier league.
The statistical community of the present study contained all the clubs that participated in 12 seasons of Iranian football clubs premier league from 2001 to 2013. The whole data was extracted from the archive of Iran premier league organization and the Foolad Mobarakeh Sepahan sport club. Improvement or degradation of football clubs in each season compared to the previous season based on coach changes or stability was investigated. The data was analyzed with one-way Anova using the Gabriel post hoc test and the independent sample t-test in a significance lower than 0.05.
The results obtained demonstrated that coach stability had a significant effect on the improvement of performance, and successive changes of coaches had a significant impact on degradation of performance. These results showed that the coach changes caused a 1.48 decline in their rank on the league schedule, and coach stability caused a 1.19 improvement in their rank on the league schedule.
Generally, analysis of the results supported the hypothesis that coach stability provided enough time for employing new players and implementation of their tactics and work philosophy that eventually improved the performance of the clubs.