The health crisis caused by COVID-19 has stopped the daily lives of millions of people. Football has been no stranger to this paralysis. The return of the competition almost three months later includes a change in the regulation that allows a maximum of 5 substitutions per game and a bigger number of players can be called. However, the most important novelty is that all the remaining games will be played without supporters inside the stadium. How can playing without an audience affect the result of a game?

It is widely demonstrated that playing at home generates an advantage for the local team. The advantage of playing at home is measured by the percentage of points earned by the teams over the total points won. In the five European leagues (English Premier League, German Bundesliga, French Ligue 1, Italian Serie A and Spanish La Liga) the advantage of playing at home reaches an average value of 60.89%, ranging from a maximum of 62.25% in the Italian Serie A and a 58.35% of the German Bundesliga.^1,2 In La Liga the value is 61.66%. The factors that explain this positive effect are diverse, but the two most important ones refer to the referee’s bias and the stimulating effect of the public on the player’s behaviour.³ Some lab research has shown how fan noise can cause up to a 15% increase for a referee to take the wrong decision favouring the local team.^4,5 When there’s no environmental noise, the referee’s bias also disappears. It has also been demonstrated how the extra time is longer than it should be when the team that plays at home is losing by one goal compared to when it is winning. We also know that supporters cheers increases testosterone and cortisol levels in footballers who play at home compared to its rivals. The same effect takes place when comparing an official match to a friendly one. As Beckenbauer recently suggested, having a stimulating or dissuasive audience can be decisive for the competition.

A recent review has analysed 191 games that have been played without an audience since World War II in European football. Most of the games are after 2002 and they have mainly taken place in the Italian and French leagues. There is only one game of La Liga. The results of this review are relevant:

• If it is usual that 46% of the games are to be won by the local team, in the sample studied the percentage dropped to 36%.
• Visiting teams usually win 26% of the games with spectators, however, in the sample they won 34%.
• Playing behind closed doors reduced significantly the number of yellow cards the visitors received: the referees showed an average of 0.5 fewer yellow cards per game to them.

So, it seems that playing without fans in the stadium can change the result of a match. There’s more interesting information to think about. The big teams tend to keep their performance more stable at home or outside. Although playing at home may be very different for each team, it seems that the advantage of playing at home favours teams from small geographical areas with a very strong ethnic identity more than teams from big cities.⁶ These teams may be the most affected by playing without their supporters.

In summary, it is very probable that the positive effect of playing at home is reduced and that it may affect the final result of the championship. Coaches should prepare footballers very well to face this new competition atmosphere which completely differs from the one they are used to. In any case, we still must be cautious with these findings as there are other important factors such as the previous training made by the teams, the rivals level, or a probable scenario with injuries that can influence the outcome of the league.

Carlos Lago Peñas

References

¹ Pollard, R., & Gómez, M.A. (2014). Components of home advantage in 157 national soccer leagues worldwide. International Journal of Sport and Exercise Psychology, 12, 218-233.

² Sánchez, P.A., García-Calvo, T., Leo, F., Pollard, R., & Gómez, M.A. (2009). An analysis of home advantage in the top two spanish professional football leagues. Perceptual and Motors Skills, 108, 789-797.

³ Gómez, M. A., Lago-Peñas, C., & Pollard, R. (2013). Situational variables. In T. McGarry, P. O’Donoghue, & J. Sampaio (Eds.), Handbook of sports performance analysis (pp. 259–269). London: Routledge.

⁴ Nevill, A. M., Balmer, N. J., & Williams, A. M. (2002). The influence of crowd noise and experience upon refereeing decisions in football. Psychology of Sport and Exercise, 3(4), 261-272.

⁵Unkelbach, C., & Memmert, D. (2010). Crowd noise as a cue in referee decisions contributes to the home advantage. Journal of Sport and Exercise Psychology, 32(4), 483-498.

⁶ Pollard, R., & Gómez, M. A. (2009). Home advantage in football in South-West Europe: Long-term trends, regional variation, and team differences. European Journal of Sport Science, 9(6), 341-352.