What the media won’t tell you about football, part 3 – referee home bias

 

 

Why the media won’t handle certain football topics

Venue bias is one of the biggest stories in football that the media won’t touch.  The evidence that it exists has been known since the earliest days of the football pools when punters were given far less reward for predicting home wins than draws.   But what was not understood until this century was why it happened.  Why do home teams have an advantage over away teams?

The issue has come to the fore twice in recent years.  Once through a series of breakthrough research programmes undertaken by university based researchers, and then by the unusual results we all saw when football in England was played without crowds, and the pattern of results changed.

The table below gives the percentages of home wins, draws and away wins season by season, with the final column showing the difference in percentage points between the home and away figures.  A popularised report on the move to matches without crowds was published by Sky Sports.  It is an interesting read in that the article, without any supporting evidence at all, puts down the change in results to the effect the silence has on the home team players.   There is no evidence to support this, it was just a statement that was made, and repeated and repeated until it became the norm.

In fact it was a totally false analysis, as research showed, but why did it get so much traction?  Was it because it was simple and easy to understand, and publishers and broadcasters like Sky couldn’t be arsed to find the truth, or was it because there was a deliberate push to get this version accepted, rather than what turned out to be the truth?

Now if you are a regular reader with a good memory you may recall that during the earlier parts of the pandemic, Untold decided to follow up on research being undertaken by Ignacio Palacios-Huerta, who was on the board of Athletic Bilbao for seven years and is professor of management, economics and strategy at the London School of Economics – part of the University of London (and against which I will hear nothing since the University of London is where I did my research degree).

The findings have been reproduced and openly discussed elsewhere.  See this article on home bias in refereeing decisions from the journal Science Direct, for example.

Going back to the earlier commentary, Professor Palacio-Huerta wrote it up as a report in the Review of Economics and Statistics (Volume 87 | Issue 2 | May 2005 p.208-216 if you are currently doing a PhD and want to look it up) into “Favouritism under Social Pressure.”

He started by looking at what happened in time added on at the end of La Liga matches and found that when a home team was ahead by a single goal, the referee allowed almost 30% less additional time than average.   However, if the home team was behind by a single goal the referee added on 35% more time than average. And there was more, for the larger the crowd, the more biased the referee’s adding on of time became.

Furthermore, when the away team scored in time added on then time was added onto the time added on – but even this was variable.  Referees were shown to end the game more quickly if the home team scored – responding to the whistling of the crowd.

There was another study of this type conducted in the 2006/7 season in Serie A wherein various clubs had to play in empty stadia following serious crowd incidents.   Here the significant crowd influence on the referee was removed and the home advantage with fouls, yellow cards and red cards awarded against the away side all reduced significantly.

Then the Guardian reported on research in which 40 qualified referees considered 47 incidents from the Liverpool v Leicester game. Half watched with crowd noise, half without any crowd noise.  The referees viewing the game with the crowd noise awarded more than 15% extra fouls committed against the home team compared with those watching in silence.

So that is the background.  Now let’s see how this relates to Premier League games.  Remember, if the theory that crowds affect the referees is right, then home advantage would disappear in 2020/21 when there were no crowds.

Season Home percentage of points Away percentage of points
2018/19 57% 43%
2019/20 58% 42%
2020/21 44% 56%
2021/22  54% 46%
2022/23 58% 42%

 

And so we can see it.  In the season when there were no crowds, the percentage of points awarded to home teams dropped from its regular level of 57% to 58% down to 44%.  Nothing else changed except there was no crowd noise.

We reported what was going on, as did others, and the academic research came up with the reason.  And it was nothing at all to do with the way the crowd noise influenced the players.  It was to do with how the crowds influenced the referees, as some very clever research with professional referees revealed.   

So how did PGMO and the media respond? I’ll leave that part of the story for the next episode.

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *