Football and the impact of fans
By: Jonathan Chappell
Tags: Football, Fans, Premier League, Soccer, Data Analysis

The match watching experience for all football fans has changed dramatically since the outbreak of the Coronavirus. Fans of Premier League (PL) and Championship teams have up until December only been able to watch games from afar, usually behind a TV screen. This has resulted in empty stadiums all over the country, with teams competing against each other without the usual roar of the crowd creating an atmosphere.

Several articles were written initially written about the impact of fan-less stadiums on the performance of teams — FT and The Athletic. However, since December, some stadiums have been opened to a limited number of fans. Now that a small sample of few dozen matches has taken place with up to 2,000 fans, it got my attention to investigate whether a small number of fans can make a difference and look at what the longer-term impacts of empty stadiums will continue to be on the performance of teams.

The Games With and Without Fans

Using match results from Football-Data.co.uk and code I’ve written (GitHub), I’ve compiled data from the start of the 2017/18 season for both the PL & Championship leagues to 22nd December 2020, when this article was published.

The graph below breaks down the matches that have taken place since the start of the 2017/18 season, showing where the maximum number of fans have been allowed (Maximum Fans), no fans have been allowed (No Fans) and a small number of fans have been allowed (Limited Fans).

As you’d expect, most matches have taken place with a maximum number of fans. But since the outbreak of the pandemic back in March 2020, 17% of matches in the period we are looking at have taken place with no fans. Just over 1% of matches have taken place with a limited number of fans, which is almost the equivalent of 3 gameweeks in a Championship season. In light of the fact that we only have a small sample of data for matches with limited fans, any insights are tentative until a larger sample size can be obtained.

Looking at some of the teams in the PL and Championship that have been allowed to accommodate up to 2,000 home fans, such as Liverpool, Everton, Southampton, Spurs, Bournemouth, Norwich, Brentford and Watford; they are all towards the top end of the table. Therefore, I should also caveat that the small sample of matches with limited fans could be skewed by the strong performances of these high-flying teams.

Home and Away Wins

In layman’s terms, the simplest and easiest way to understand the impact that the lack of fans has on team performance is to look at the changes in the percentage of home wins, away wins and draws. The diagram below breaks this down (rounding may mean results do not equal 100%).

For home teams where they can allow the maximum number of fans in, they experience a clear advantage. This is shown with home win percentage significantly higher than that of the away team — nearly 15%.

What is striking is that when fans have not been allowed into stadiums, away teams win percentage increases by 5%. It is easy to build a narrative that reinforces this whereby no home fans boo or jeer the away side, away teams feel more emboldened to take on the home favourites and impose their own tactics to try and get all three points. We will investigate later at how this has been borne out in goal scoring for home and away teams.

Although home teams do experience a drop off in win percentage when they are unable to have any fans, they still have a sizable advantage over the away team when it comes to winning matches. Whilst it’s clear that not having fans does have an impact, home teams still dominate without them and this could partly be explained by the familiarity of surroundings and less travel, but it would be interesting to find out more why home advantage is still present without fans.

Finally, looking at the small sample where limited fans have been allowed, it is interesting that home win percentage and away win percentage has almost reverted back to the same levels as when a maximum number of fans were allowed. Even the atmosphere created by a crowd of 2,000 supporters suppresses the drive of the away side and gives the home team confidence to push on for the win. It will be intriguing to see if this trend carries on for the rest of the season.

Goal Scoring

The key driver in determining who wins any football match is goals. The chart below breaks down how goal scoring has changed for home and away teams in the different fan settings.

The goals metric begins to explain some of the results we can see in the win percentage numbers. When maximum fans are allowed into stadiums, home teams tend to score over 25% more than the away teams and this partially drives the home-field advantage. It could be said that home supporters push their team to shoot more — 13.7 home shots vs 11.2 away shots, giving the home team more goal-scoring opportunities, resulting in more home goals and victories.

When no fans are present, home teams without the encouragement of their supporters become significantly more goal-shy, whilst away teams tend to slightly improve their goal-scoring. This can be seen in the shot numbers with home shots falling to 12.1, away shots slightly decreasing to 11.0 and both converting at around the same rate of just over 11%. This goes some way to explaining why away teams improve their win percentage and home teams are not as dominant as usual, however, with goal-scoring being so close between the two teams we might also expect the number of draws to increase and that actually hasn’t been the case.

Finally, home goal-scoring, shots and conversion rates almost return to normal levels with the presence of 2,000 fans providing the team with the necessary motivation to score and this enables home win percentage to climb back to near usual levels. The largest impact of having a small number of fans is on the away side with goal-scoring reducing as a result of a significant fall in shots to 9.6 per game and conversion rate decreasing to 9.3%. With this sharp drop-off, we would assume that away win percentage drops below that of when maximum fans are allowed, yet this has not been the case. It will be interesting to see if this impact on away goal scoring is a longer-term trend or a fact of the small set of matches for which we have a limited number of home fans.

Conclusion

From the analysis, we can see that having the maximum number of fans at games gives the home team a significant advantage. With the outbreak of coronavirus and the ban on fans in stadiums, we have demonstrated that away teams have managed to chip away at this benefit of playing at home, partially as a result of improving their own goal-scoring, but also limiting the goals of the home side. What is most interesting from the analysis, is that when just 2,000 fans can attend, they seemingly make a significant impact on the end result and can make up for the rest of the supporters who are unable to attend.

Leeds United manager Marcelo Bielsa has mentioned that this small number of fans attending will have an impact on the result, saying, “perhaps there could be a rule that states that if fans are not allowed in all stadiums, then they should not be allowed in at all until everybody is allowed to have them in.”

If the trend continues then Bielsa would be correct in his statement, and those teams such as Liverpool, Everton and Bournemouth that will be allowed, in the short-term to have supporters attend, will be at a significant advantage versus the rest of the PL and Championship.