Research has been conducted looking into whether referee’s are biased towards certain teams or individuals. Manchester United tend to have a reputation from rival supporters for ‘Fergie time’, gaining more penalties than other teams at home, especially with Howard Webb. Marouane Fellaini even stated that referee’s were biased towards English players following his head butt on Ryan Shawcross.
For this article I am going to focus on comparisons between home and away games in relation to the number of fouls lost before cards are issued. The results I found were interesting, however some factors could have influenced the reliability of the data including the magnitude of the foul given away. For example fouls can vary hugely. A two footed challenge is of course going to draw a different result to an attacker leaning over a defender from a corner. I have taken data from every game so far this season so there is more chance this will be evened out and the data therefore accurate.
This first graph above shows comparisons of free kicks lost per yellow card (F/Y), home free kicks lost per yellow card (HF/Y) and away free kicks lost per yellow card (AF/Y). All data will be presented as mean ± standard deviation (SD). This is based on all twenty teams. As you can see, there’s variation in the data. For both home and away combined there was an average 7.7 ± 1.1 fouls given away before a yellow card was given between the whole team. This doesn’t show us much, however when we look at home and away individually, we can see that a lot more fouls are given away at home (8.8 ± 1.6) than away (7.0 ± 1.5) before a yellow card is presented.
It is hard to conclude why this difference occurs. Is it crowd influence on referee’s decisions? The change in tactics used by the manager for home and away games?
I then decided to look more closely at these factors to try and find the answer. For the change in tactics, I found out the Total fouls lost for both home and away games. At home, for all teams, there was an average of 165.5 ± 15.0 given away. Away from home there was 172.7 ± 18.9. This is for all the games played so far. So more fouls are lost when playing away, which could conclude that teams adapt a more aggressive mentality, or more bad decisions are made due to the increased pressure when playing away. So maybe this is the reason for yellow cards being shown more often than when at home?
Now I will look at crowd influence as a factor, to see if it impacts referee’s decisions. The graph above shows the same data as before, however the focus is on comparing the top and bottom 10 teams based on average attendances for this season. You can see for yourselves there is little difference between the two variables. For both home and away similar results are shown. So to an extent, it can be said that the venue, or just the amount of fans present does not influence a referee’s decision in terms of issuing cards. However, there may still be effects of crowds on other aspects of the game including penalties awarded or denied.
Finally, the graph above shows individual team comparisons. I’m not going to talk too much about these as I don’t think they will influence conclusions but I’ve put it up so people can have a look at their supported teams. I talked earlier about Manchester United being scapegoated for having a 12th man in the referee. Well based on the data I looked at, you can see that Liverpool have the greatest difference between home and away. Away from home they average 5.9 free kicks per yellow card, where as at home they have over double this with 12.9 lost free kicks per yellow.
Only five teams (Arsenal, Everton, Newcastle United, Norwich City and Reading) had a higher amount of AF/Y than HF/Y with the quintet only having small differences.
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All of the stats from this article have been taken from the Opta Stats Centre at EPLIndex.com – Subscribe Now (Includes author privileges!) Check out our new Top Stats feature on the Stats Centre which allows you to compare all players in the league & read about new additions to the stats centre.[/box_light]