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 Norwich 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 earlier post on our desire to recruit Norwich fans who are qualified refs to help us in this venture.
We reviewed 11 games in which Norwich was involved. Rather good for a new team in the PL. So we thank the TV stations who picked them up on a few occasions. 11 games in the PL means 28,95% of all their games. We are nearing the 30% mark with this team. So slowly the numbers will become a bit more accurate.
But then again if you think it should be more and if you are a ref: what is stopping you from joining us?
Let us see how the refs in general did in the games where Norwich was one of the teams involved. A warning the first two graphics tell you nothing about any possible bias. This score is for both teams involved on the pitch.
So Norwich a mid table team and a very middle of the road result. They come very close to the league average of correct decisions. Now if you are satisfied with the overall league average (be my guest – I’m not) you can be happy about this. As said I think the overall league average is too low so these numbers are also a bit low for me. But at this time of the report Norwich can only say that they were a bit treated like the rest of the league.
Let us see how the different types of decisions was.
If we look at the different decisions type we see that the goals are almost the same as the league average. So again Norwich will feel no need to complain. I still think this is too low to be acceptable.
The offside decisions are also almost the same as the league average. A league average of 99% claims Mike Riley. We only come to some 90%.
The other decisions are also bang on, or very close to the league average. This sounds the most boring team report so far in the series.
Ah, the penalties we see a difference. Slightly better than the very low league average. But only a small margin of 2% better. So we don’t get wild about it.
The red cards in the Norwich games have a low score. Zero is the final result, it can’t get lower than that. So no surprise in this decision the score is lower compared to the league average.
And also the yellow cards are lower than the league average. Not even 50% of the cards have been given correct.
The next step is to see if we can find if there is some kind of bias in those fairly average numbers.
First the un-weighted numbers. When you go away from home you can expect that you have to overcome a negative away bias of some 1.826 bias points decisions. But Norwich is a somewhat lucky team as they received in total of those 11 games and in the 5 away games we reviewed a positive bias from the refs.
In fact they got a more positive bias away from home than they got at their home ground. Because in average you come to a positive home bias of 1.826 and Norwich only got a positive bias of 1.000. The end result is of course a positive bias in total.
If we put weight on to the decisions you can expect a negative away bias of -2.619 against you. Norwich got a positive bias of +3.200 in their favour. So almost the reverse situation to what could be expected.
And at home they got almost the normal bias that we have found in the whole league. So if we put weight on the decisions the positive bias in general remains. And again this results in the strange fact that away from home they had more decisions going their way compared to being at home.
Let us move on to the refs who did their games.
We had 10 different refs in those 11 games. 6 of those refs had a negative bias against Norwich and 4 had a positive bias. 3 refs had a rather small negative bias: Jones, Oliver and Clattenburg. They are a bit middle of the road for Norwich.
The bad refs for Norwich have been Attwell, Marriner and Walton.
On the other side of the table we find Dowd, Foy and Webb with a rather high positive bias score. Anthony Taylor is the most popular ref in Norwich I think. With two games done he has the highest positive bias swing in his numbers.
Let us move on to the numbers where we put weight on the decisions.
If we put the weight on the decisions we see a slightly different picture. We now have 5 negative and 5 positive refs. Michael Oliver has gone form a negative -1.000 swing to a positive +1.000. This can be explained by the fact that he made some mistakes in general but missed one big call that went against Norwich. By the look of the swing it could be that he missed a yellow card in that game that should have been given against the opponent.
With the weight added Marriner becomes the worst ref for Norwich, followed by Attwell. Jones and Walton also have a rather bad negative bias swing. Clattenburg remains stable with a very close to zero score but still negative.
We notice a bit of a big rise in the numbers when we look at the refs who had a positive bias in favour of Norwich. Dowd, Webb and Foy have been rather kind one could say. Anthony Taylor has been maybe a bit too kind in his two games he did Norwich?
If you look at this last table you see that whenever the bias against Norwich reached the -10 mark they dropped points. The good thing (from a league point of view) is that there are a lot of games with a rather equal bias and also with a small bias score.
A very middle of the road score from the refs in the games that had Norwich playing a part.
The final outcome is a positive bias from the refs but a rather small one compared to other team we have seen so far. We also notice that when the refs turned their back on Norwich they suffered from the wrong decisions made by the refs.
When the refs favoured them they ended up with some points but mostly they got a draw as the final result.
The refs didn’t went out to destroy Norwich. When they showed a negative bias it cost Norwich points. A positive bias not always. The most amazing part is that Norwich got a better treatment away from home compared to their home games