Proving unconscious bias by referees is rife in the Premier League: penalties

By Tony Attwood

If you have been following this series, you’ll know that it has been shown, through research undertaken at London School of Economics (part of the University of London) that referees are clearly influenced by the crowd.  This in turn explains why the bias towards there being more home wins than away wins that we have taken as normal across the years, slipped away immediately clubs started to play in empty stadia.

Because of this bias we might imagine that there could be a similar bias to be found in terms of penalties awarded to home teams, as opposed to away teams.

With data taken from MyFootballFacts.com we can see that between 1992/3 and this season, 61.46% of penalties were awarded to the home team and only 38.54% to the away team.

Now this could be explained through the notion that the home team attacks more, and as a result the home team wins more often.  But as we have noted the LSE research revealed that the home team wins more often because of crowd induced referee bias – which in turn explains why in empty stadia the figures have changed so dramatically.

The question therefore is, at a time when home teams have stopped having an automatic advantage overall, has the position on penalties also changed?  In short, are away teams getting more penalties now that the stadia are empty?  And if so why?

Detailed figures are given at the end of this piece, but in summary we can notice this:

The total number of penalties given each year varies significantly from 52 (2001/2) to 106, (achieved in 2009/10 and 2016/17).

The percentage of these given to the home team also varies from 48% (2001/2 and 75% (1996/7).

But the only seasons in which the home teams have fewer penalties than the away teams were 2001/2 48% and  2019/20 (49%).  In the current season the number of penalties given is 34 to the home team and 33 to the away team.  Thus two of the three seasons where away teams and home teams were just about equal in terms of penalties, were the two seasons with games behind closed doors.

So what can we conclude from this?

Just as referees are biased towards home teams in general when there is a crowd present, so they are biased towards home teams when it comes to giving penalties when there is a crowd present.  With the crowd present there is just a 1 in 18 chance that the home percentage will drop below 50%, and when it did it dropped by just 2%.

Although we have no experiments to show that these variations are due to the crowd, given that this has been proven in relation to fouls, the rational and logical explanation for this bias, is referee bias caused by the crowd.

In short we are not saying that referees are biased per se, but that they are biased because of crowd pressure.

Unfortunately PGMO has been vigorous in denying this, claiming in various statements that it’s decision making is anything from 98% to 99.5% accurate (depending which statement one reads).  This clearly is not true.

Here is the table of evidence relating to penalties

Total up to and inc 2018/19
2,119
1319
800
62%
Total for 2019/20 & 2020/21
159
81
78
51%
Season Total Penalties Home Penalties Away Penalties Percentage of penalties given to the home team
1992-93 61 45 16 74%
1993-94 82 50 32 61%
1994-95 69 40 29 58%
1995-96 55 34 21 62%
1996-97 64 48 16 75%
1997-98 61 44 17 72%
1998-99 53 32 21 60%
1999-2000 66 42 24 64%
2000-01 57 37 20 65%
2001-02 52 25 27 48%
2002-03 64 40 24 62%
2003-04 79 54 25 68%
2004-05 74 42 32 58%
2005-06 73 49 24 67%
2006-07 105 64 41 61%
2007-08 82 51 31 62%
2008-09 83 58 25 70%
2009-10 106 68 38 64%
2010-11 101 62 39 61%
2011-12 99 58 41 59%
2012-13 83 53 30 64%
2013-14 87 48 39 55%
2014-15 83 51 32 61%
2015-16 91 53 38 58%
2016-17 106 66 40 62%
2017-18 80 51 29 64%
2018-19 103 54 49 52%
2019-20 92 47 45 49%
2020-21 67 34 33 51%
Totals 2,278 1,400 878 61%

This can be explained by referee bias resulting from crowd pressure, in keeping with the LSE research.

However this leads to another disconcerting conclusion.  If there is unconscious referee bias both in the LSE reseach and here, where else can it be found?  Can it be found in, for example, the awarding of free kicks, yellow cards, and fouls?

Given that we have found bias in decisions late in the match, and in penalties, it would seem that the logical and reasonable answer is yes.  So the next step is to go looking for unconscious bias by referees in the areas of penalties, yellow cards, fouls and free kicks.

That’s what we turn to next.

7 Replies to “Proving unconscious bias by referees is rife in the Premier League: penalties”

  1. “In short we are not saying that referees are biased per se, but that they are biased because of crowd pressure.”
    This seems a huge shift from the narrative on this site that there is in fact a conscious bias by a corrupt refereeing organisation, with Mike Dean the main culprit.
    There is unconscious bias everywhere in all walks of life because we see what we expect to see,( just like there is unconscious racism). If a player gets a reputation for diving, deserved or not, he is less likely to be awarded a penalty when he throws himself down in the box than someone who “is just not that kind of player”. That is unconscious bias at work.
    What you have highlighted on this site is several interesting factors that contribute to this unconscious bias not being randomly distributed. e.g the disproportionate representation of referees with northern connections. Look forward to seeing more of this type of insightful analysis.

  2. Against Newcastle Utd, first in the FA Cup and second in the PL all at the Ems in the next Arsenal two home matches. But will the PGMO referees for these two Arsenal next two home matches be fair to the Gunners to award them any penalties that they legitimately won in the game during the playing of the two matches?

    But not wave off the penalty awards to Arsenal to deny the Gunners taking them to convert them for Arsenal. Which if Arsenal are awarded could potentially determined the outcomes of the two matches to the favour of Arsenal if the Gunners convert them. But legitimate penalty awards won by the Gunners in the two Newcastle matches are not deliberately denied Arsenal.

    But whichever way and manner that the PGMO referees decided to officiate in these next two Arsenal home matches, be it fairly or unfairly to Arsenal in the game. But I think with the recent game winning resurgence that has engulfed the Gunners in recent past weeks that saw Arsenal won thrice on the trot in the PL, the Gunners are looking to have now found the antidote that when they use it in their game playing neutralize any poisonous PGMO Arsenal match refereeing that could be orchestrated against the Gunners in the PL and in domestic Cup game such as in the FA Cup to be winning their matches.

  3. Against Newcastle Utd, first in the FA Cup and second in the PL all to be played at the Ems in the two next Arsenal home matches. But will the PGMO referees for these two Arsenal next home matches be fair to the Gunners in their games to award them any penalties that they legitimately have won in the game during the playing of the two matches?

    But not wave off any deserving penalty awards that the Gunners have won to deny them taking the penalties to convert them for Arsenal. Which if Arsenal are awarded could potentially tilt the outcomes of the two matches to the favour of Arsenal if the Gunners convert the pens awarded to them. Legitimate penalty awards won by the Gunners in the two Newcastle matches should not deliberately be denied Arsenal by PGMO match refereeing system.

    But whichever way and manner that the PGMO referees decided to officiate in these next two Arsenal home matches, be it fairly or unfairly to Arsenal in the game. But I think with the recent game winning resurgence that has engulfed the Gunners in the recent past few weeks that saw Arsenal won thrice on the trot in the PL, the Gunners are now looking to have found the antidote that neutralized the PGMO in their Arsenal match poisoning when the Gunners have used it in their recent game playing in the PL.

    Therefore, the PGMO employing any further match playing toxic against Arsenal to poison the Gunners in their next matches in all competitions doesn’t look it will work as the Gunners now look to now have the antidote in their game playing to void any PGMO toxic that could be directed against Arsenal. Thus, paving the way for Arsenal to win the match they’ve won unrestricted by the pGMO in the PL and in all domestic Cup competitions such as in the Carabao Cup games (late) and the FA Cup matches guaranteeing the Gunners winning their matches henceforth with.

  4. Dont get fooled by this unconcious bias bullshit!! The officials may be unconcious because they are so damned stupid but never in a million years are their bias unconcious.

    One only has to observe the officiating to see the cheating that is going on. It is so obvious that the game is no longer a sporting competition.

  5. Brest 2-0 Nice. On loan Arsenal’s centreback to Nice this winter window William Saliba played the full match without been substituted.

  6. Dublin Gooner and Menace: I fear I have not worded this well. What I am saying is that in this article I am focusing on unconscious bias, which now with these figures can be proven.
    That is not to say that there is no conscious bias as well, but I think it is worth separating the two so that the objections to the argument put on this site can be dealt with.
    I’m grateful to you both for bringing this up and I will try and clarify where my thinking is going on this in the next article

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