Improved training of football referees and the decline in home advantage post WW2

Objectives Research has identified a decline in home advantage (HA) in a number of professional leagues since World War 2 (WW2). The purpose of the current study was to identify whether the decline in HA in English and Scottish Professional Football Leagues is mirrored by the radical transformation in the training of referees post-WW2, thus providing a new insight into the cause of HA. Design A longitudinal quasi-experimental design. Methods HA was calculated for each team at the end of every season for the four English and the Scottish Premier League post-WW2. We also compiled a list of events, statements and quotations to illustrate the dramatic change in the way referees have been trained (physically and psychologically), and assessed over the same period. Results We observed a systematic decline in HA in professional English and Scottish leagues post-WW2, but with the steepest decline observed in lower divisions with smaller crowds. Of the factors thought to influence HA, crowd support appears the most consistent with these observations. Crowds are known to influence referees’ decisions to favour the home side. However we argue that improved training of referees since WW2 has contributed to an improved ability to make objective decisions and a greater resilience to crowd influence, which explains the decline in HA but also accounts for the steeper decline observed with smaller crowds. Conclusions The continued existence of HA, and the less steep decline observed in top leagues suggests that referees’ judgments are still not immune to the influence of larger crowds.