Chelsea and the refs last season

Last season a group of qualified referees reviewed more than 40% of the EPL games. The reviews themselves were based on full match video footage with the advantage of video technology features such as slow motion and pause.

By reviewing those 155 games we have made a database of more than 7000 decisions that have been judged by our panel of dedicated and qualified referees.

The numbers you will see are based on those decisions and those reviewed games.

Below is the review we published in the summer on Chelsea and the refs.  We are publishing it again because we hope to attract more referees who are willing to monitor what the refs in the Premier League get up to.  If you would like to help us please have a look at our post which gives the full details.

So here we go with our review of Chelsea last season…


Untold Vs PGMOL - Chelsea 2011/2012

And look at those numbers! We have done 32 games from Chelsea last season. That is a total of 84,21% of their games in the PL.  I think this is really an awesome number of games we did and no matter what the outcome will be, it will be based on very reliable numbers.

Now some might say: and what about the 6 missing games? Yep, it is a bit of a shame that we couldn’t review them. This is down to the fact that the TV stations in the countries where the referee reviewers live didn’t always gave the Chelsea games and of course because we could have done with a helping hand from qualified referees. So if you think we should have done the other 6 games also and you are a qualified referee I just want to ask you to make yourself known and join our ranks. This is an Arsenal site but we would love to have referees on board who support other teams.

So after this round of advertising ourselves a bit let us see if the refs were competent in the Chelsea games?

PGMOL Vs EPL - Basic Competency - Chelsea 2011/2012

Well it all depends on how you look at these numbers. If you are satisfied with the overall league average and you think the refs have done great with that… The number of Chelsea is not that bad. If you however think that refs making  1 mistake in every 4 calls is not good (that is what I think) then the fact that Chelsea comes close to the league average is saying: the refs were mediocre in the Chelsea games.

And if we put weight on the decisions we see the same picture. Just slightly above the league average. This reminds me of an idiom that exists in my language that goes: in the land of the blind, one eye is king. This is how I feel about that score.

Not good enough but well we somehow have learned to live with mediocrity.

Let us have a look at the different type of decisions.

PGMOL Vs EPL - Basic Competency Breakdown - Chelsea 2011/2012

In this graphic we don’t know who got the benefit of the wrong decisions. We only look at the decisions in the Chelsea games and if they were correct or not.

Can any football supporter be satisfied knowing that 1 goal decision in 10 is wrong? I’m not. It doesn’t matter if it is only just below the league average. The league average on goal decisions stinks.  This is the decision type that determines who gets the points, so it has to be as correct as possible.

Let us move on to the offside decisions. People who have been around know that Mike Riley claimed that 99% of the offside decisions are correct. In Chelsea games we only came to 87%. That is 12 % below what is promised. So rubbish result for the refs and the assistants.

Let us move on to the other results. The fouls in the middle of the field. Slightly better than the league average that is  71.96%. But before you order the champagne and start a wild party: this still means that 1 decision in 4 is wrong.  I’m not that impressed by that number you know.

Let us move to the penalty decisions. And this decision type is a good one compared to the league average. In fact this is the highest result of the top teams in the league. There are 3 other teams who had a better score on this but that was only based on 10 games or less. So all in all this sounds a good result.  73% correct penalty decisions and almost 11% better than the league average.

The joy for that decision type goes out of the window when we look at the red card decisions. Only 17% correct and that is one of the lowest in the league. So really not good at all.

The yellow card decisions are at 57%  just above the league average. Which is not that great to be honest but well in the land of the blind…

But let us now open our eyes and see if we can find if someone benefited from the wrong decisions from the refs? So from now on we will be looking at the possible bias we can find in the wrong decisions.

PGMOL Vs EPL - Incorrect calls Breakdown - Chelsea 2011/2012

Despite Mike Riley claiming there is no bias whatsoever in the PL we have found that there is a home and away bias.

And when you go away from home you can expect a negative bias from -1.826 against you. Chelsea on their travels (and our report includes almost all their away games) had only a negative bias of -1.000. so they had a negative bias but smaller than the league average.

On the other hand if you play at home you can expect a positive bias of +1.826. In this case we found that Chelsea had a positive bias of +1.933. So slightly higher than the league average.

And the final result is that this has lead to a small overall bias in favour of Chelsea.  In fact this is smallest positive bias of all the biases we have found, when we found a positive bias.

If we put weight on the decisions we can expect a negative away bias of  -2.619 on average.  For Chelsea we found a negative away bias of -1.588. So not as much as the league average but a negative bias never the less.

In the home games one can expect a positive home bias of + 2.619 and the final number for Chelsea is only +2.419. So when we put weight on the decisions we get a smaller negative away bias but also a smaller positive home bias.

The final outcome is a small total positive bias in favour of Chelsea on those 32 games. But this is the smallest positive bias we found of all teams with a positive bias. Let us now look at the different referees in the games.

EPL vs PGMOL - Incorrect calls Breakdown by Referee - Chelsea (Un-Weighted) 2011/2012

We had 14 referees in those 32 games. 7 referees had a negative bias against Chelsea. 1 ref had a zero bias. Well done Martin Atkinson. And 6 referees had a positive bias in favour of Chelsea.

Chris Foy was the worst ref against Chelsea last season.  His negative bias was grotesque in fact. Dowd, Oliver, Webb had a bad negative bias score against Chelsea. Probert and Dean were just acceptable. Mark Clattenburg was close to the zero mark so well done.

Refs with a positive bias were Friend with a not that big one. But then it goes sky high. The score of Jones, Halsey, Walton and Mason were highly favourable for Chelsea.

Let us see what happens if we put weight on the decisions.

EPL vs PGMOL - Incorrect calls Breakdown by Referee - Chelsea (Weighted) 2011/2012

Of course we have the same 14 refs and again 7 refs with a negative bias. 6 refs with a positive bias score. And one ref with a zero bias score: Mark Clattenburg is that ref.  A great result I would say and this is where we would like to find all the refs.

But we have other refs in this report. Why don’t you just take a look at the score from Chris Foy. That surely must be one of the biggest negative scores I have seen from any ref. This is too ridiculous for words in fact. Phil Dowd and Oliver also have a very bad negative score against Chelsea. And now that we have put weight on the decisions we also notice Webb joining in the very negative numbers. As does Probert and Atkinson who made a mess of his zero score when we put weight on the decisions. Mike Dean was rather all right.

On the positive side of this graphic we find Friend with a moderate positive bias, also well done I would say.  Halsey and Jones are a bit too positive to be good. The score from Walton, Marriner and Mason is beyond what can be considered acceptable.

PGMOL Vs Chelsea - Incorrect calls Seasonal Handicap - Chelsea (Weighted) 2011/2012

In this graphic we see two overly negative bias numbers for Chelsea and both lead to Chelsea dropping points in those games (week 1 and week 9). This is a fine example on how difficult it is for any top team to win against the negative bias from the ref.

When the bias turned to acceptable levels Chelsea picked up the points. But when the bias turned against them, they dropped points again. But they also dropped points when they had an overly positive bias. So it doesn’t always work. A team can beat the ref but it can also happen that despite the ref his co-operation, it still goes wrong at times.

Half way through the season it was clear that this Chelsea team was not in for the league title. And the bias in the games became more to a reasonable level. Decisions going for and against in a very random order.  But still a few very high negative bias scores with rather too many important decisions going against Chelsea.

In one game they got very lucky and got two important big calls that won them the game. And after that the bias suddenly dropped to very low levels. One could wonder if something has been said somewhere.


In these numbers you can clearly see how important it is to have a ref that makes the correct decisions. When the ref was making a mess and the decisions were negative for Chelsea they dropped points. And on the other hand when things went for them, they picked up the points.

You can say all you want about players, managers but at the end of the day when the refs make a mess of your games you stand there helpless and you can do nothing about it.

This entry was posted in Chelsea. Bookmark the permalink.

One Response to Chelsea and the refs last season

  1. rabiu suleiman says:

    Chelsea have always been at the receiving end in the pl when it come to decision making by the referees.The season may even be the worst,going by two marches played so far the decisions taken by referee disfavour chelsea.

Leave a Reply

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