Any suggestion that referees are accurate and consistent over fouls is a myth

By Tony Attwood

• Clubs are being encouraged to tackle more and more by referee’s approach.

Most yellow cards are given in professional football for bad tackles.  Which might make one presume that there could be some sort of general relationship between the number of tackles and the number of yellow cards that Premier League clubs receive.

But this is not what we find.   Indeed to see the phenomenal variation that there is in the way clubs are treated we can note that Manchester United, this season, are putting in 4.71 tackles before they get a yellow card.   Liverpool are getting away with 15.55 before they get a card.  Put another way, Liverpool are delivering 330% more tackles before the yellow card is waved, than Manchester United.  (Figures from WhoScored)

Now looking at the two clubs we might agree that Manchester United’s tackling this season is a bit wayward, but is it over three times worse than Liverpool’s?   It is hard to see that watching the matches on TV.

And just in case you think these figures represent reality on the pitch, try this.  West Ham can put in almost twice as many tackles as Brentford before getting a yellow.

And Leicester despite their current league position of being bottom of the league with the second worst defensive record in the league can put in twice as many tackles as Brentford or Aston Villa before getting a yellow.  Yet logic, and indeed watching them on TV, suggests that Leicester are not twice as good at tackling as Brentford or Aston Villa.

So could it be that simply the more tackles a club puts in, during a game, the more yellow cards it is going to get?  

No, not in the slightest.    Brentford have the fourth lowest number of tackles this season, which suggests that they are not flying in with the tackles anywhere possible, as for example Leeds and Chelsea are, and yet they have the third lowest number of tackles they can get away with before a yellow card is waved in the direction of one of their players.

Just how unrelated the number of tackles is to the number of yellow cards we can see below. This table is in the order of the number of tackles each club puts in per game this season.   And as we can immediately see the number of tackles per game from West Ham and Brentford is similar, yet Brentford are getting yellow cards almost twice as often as West Ham.

 

Team	Tackles per game	Yellow Cards per game	Tackles per yellow card
1. Manchester City	10.2	0.66	15.45
2. Liverpool	13	0.83	15.66
3. West Ham	13	1.17	11.11
4. Brentford	13.5	2.33	5.79
5. Arsenal	15	1.83	8.19
6. Leicester	15.2	1.17	12.99
7. Manchester United	15.7	3.33	4.71
8. Aston Villa	16.5	2.5	6.60
9. Newcastle	16.7	2.00	8.35
10. Nottingham Forest	16.8	3.00	5.60
11. Brighton	17.2	1.66	10.36
12. Southampton	17.7	1.33	13.31
13. Tottenham	17.7	2.33	7.60
14. Crystal Palace	18	1.83	9.84
15. Bournemouth	18	2.00	9.00
16. Wolverhampton	19	2.00	9.50
17. Everton	20.3	1.16	17.5
18. Fulham	20.7	2.83	7.31
19. Chelsea	21.5	2.00	10.75
20. Leeds	24.2	2.16	11.20

 

To make sense of this crazy data we’ve taken some of the extremes in the figures to see what they mean.

Low number of tackles

Four teams show up here but the number of tackles they can put in before getting a yellow card ranges from 5.79 for Brentford, to almost three times as many for Liverpool!

 

Team	Tackles per game	Yellow Cards per game	Tackles per yellow card
1. Manchester City	10.2	0.66	15.45
2. Liverpool	13	0.83	15.66
3. West Ham	13	1.17	11.11
4. Brentford	13.5	2.33	5.79

 

High number of tackles

Putting in a high number of tackles does not result in getting consistently more yellow cards in all places.  Low tackling Brentford get more yellow cards than high tackling Chelsea and Leeds.   Leeds put in almost twice as many tackles as Brentford but have a lower number of yellow cards in the season!

 

Team	Tackles	Yellow Card	Tackles per yellow card
18. Fulham	20.7	2.83	7.31
19. Chelsea	21.5	2.00	10.75
20. Leeds	24.2	2.16	11.20

 

Arsenal have of course long been aware of this sort of problem, which is why after Arteta arrived he changed the tackling regime at Arsenal and cut the number of yellow cards in half, thus greatly increasing the choice of players he had each week during the latter part of the season.

So what is going on?

The Explanations

1: Corruption.   

This is the simplest idea to put forward.  Referees are trying to avoid giving cards to certain teams because they have been bought.  Obviously, we have no evidence of this and although this might be true we really have to eliminate every other option before we draw this conclusion

2.  Some clubs have clumsy defenders others have defenders who know how tackle.

Maybe, But are Fulham’s defenders twice as good at tackling as Everton’s?   Are Southampton’s defenders almost on a parr with Liverpool and Manchester City defenders when it comes to the ability to tackle cleanly,   Are Manchester United defenders almost four times as clumsy or dirty as Manchester City’s?

3.  The more you tackle the lower the percentage of yellow cards.

I’ve put this idea forward myself as I have gathered data, but really, it doesn’t work very well across the whole league.  Yes the argument works with Liverpool and Manchester City, but then it breaks down. Leicester are putting in more tackles per game than Brentford, but getting considerably fewer yellow cards.

4. Reputation

Do some clubs have a reputation among officials as being clean and others dirty?

Now this one I can believe. Manchester City, Liverpool and West Ham are all thought of in the media as football-playing teams who don’t engage in any sort of dirty tactics.  So they can put in more tackles per yellow card.  But that doesn’t work with Leeds who can put in more tackles before a yellow card is shown, and Leeds certainly don’t have a good reputation.

5.  The number of tackles per game

This one I do believe.   Referees are not using an absolute measure of tackling to penalise bad tackling with yellow cards, but use the warning to keep the number of yellows down.  So for clubs that do engage in high levels of tackling, the number of yellow cards per tackle goes down and referees become more lenient.

In this scenario, Brentford’s problem is that they don’t tackle enough.  If they tackled more, the number of tackles they would get away with without a yellow card would increase.

Conclusion

Whichever explanation we look at, these figures are highly unsatisfactory.  For these figures to be a fair reflection of what happens we have to accept that  Leicester’s defenders are around three times more accurate at tackling than Manchester United’s.  Are Southampton’s defenders almost twice as good as Tottenham’s?  Forget our bias for a moment – is that really so?

In fact the most reasonable conclusion we can draw is that the handing out of fouls, and yellow cards for fouls, is not always related to each individual tackle, and any pretence of referee accuracy in this matter is an utter myth.

• Suddenly a key set of referee statistics does not appear.  Why is that?