On Thursday 28th March the following podcast was recorded on the A Celtic State of Mind platform. You can view it here or listen wherever you consume your pods.
In the third written piece as follow-up, I consider how likely a penalty is to be given and what the trends are in awarding and conceding penalties in the SPFL Premiership.
Likelihood of Penalty Awards
We’ve considered whether the penalty, and other big calls, were correct or not during the last two and a half seasons an independent expert has been running the rule over the video evidence.
But how many penalties could be considered “normal”?
To do this I have used “Touches in the Opposition Box” as a proxy for penalty opportunities. You cannot win a penalty without getting the ball into the opponent’s penalty area. This premise is supported by this article from the European Journal of Sport Science.
For this analysis, I recorded all touches in the box for and against each Premiership side between 2020-21 and to 2nd January 2024 of the current season. I then calculated how many touches in the box each team and their opponents have per penalty awarded and conceded.
Penalties Conceded
Here are the results for penalties conceded:
On average in the SPFL Premiership, teams concede a penalty every 147 times their opponent has a touch of the ball in their penalty box.
Champions Celtic concede a penalty every 142 times their opponents enter their penalty area.
The major outlier in this sample is The Rangers.
The opposition needs to get into The Rangers penalty area 372 times on average before a penalty is awarded. With a Z-Score of -2.68, this is outside the 95 percent deviation from the mean and is therefore statistically significant and is the only result to be so.
This suggests that The Rangers have substantially better defenders than the rest of the league in that they are incredibly careful in not committing fouls in the penalty area. Yet despite this, Celtic have conceded 100 goals over the period in question and The Rangers 92, very similar.
Penalties Awarded
If we then look at how many times each team must get into the opponent’s penalty area to win a penalty:
The Rangers achieve a penalty on average every 147 entries into the opposition penalty area, the league average.
What is curious, however, is that the only statistically significant outlier, with a Z-Score of -2.28 is perennial Champions and highly dominant Celtic.
Celtic must, on average, get into the opposition penalty area 203 times before converting that possession into a penalty. The other teams that struggle in this regard are all those who are normally near the foot of the table such as Ross County, St Johnstone and Kilmarnock.
None are as statistically significant an outlier as Celtic, however. This is despite Celtic having a more potent attack during this period scoring 337 goals to The Rangers 306.
In itself, does this indicate a pattern of assistance or just one of those things that will even out over a season?
Next up: are all penalties and red cards equal? Do some carry more impact than others and to whose benefit?
Note: data is correct up to January 3rd 2024.
I’ve been watching Celtic for 78 years yes that’s correct 78 years. After every game the conversations always
involved referring descions so nothing has changed in that respect in my lifetime. The only time the Celtic
board have taken on the S F A was when the sfa orderd Celtic to remove the Irish flag from flying above the
stand. Bob Kelly refused to do so telling the sfa if it meant no Celtic in Scottish football so be it
I think Fergus was pretty successful in his action against Jim Farry
I think mcann took on Farry not the sfa, either way nothing changed
The key point about Fergus vs Farry incident is that the SFA did 2 internal reviews and found no wrongdoing. Which says so, so much about their culture.
Good work. Perhaps needs a clearer visualization/explanation of z-scores though so the SFA can understand this when they drop by to read it!
“does this indicate a pattern of assistance or just one of those things that will even out over a season?”…
Think we know the answer to that, but it would be useful to see the analysis repeated by season so you can show the persistence of the assistance (you can have that as the title for the next blog ?)
The fact is that Scotland is sectarian. You grow up supporting Celtic or Rangers usually based on your religious background. Therefore as the majority of SPL referees come from a Protestant background then so too will their decisions be based on a sectarian nature.
The SFA need to be honest and admit this and bring in non Scottish referees for SPL games.
Alan, interesting and thought provoking as usual. With Celtic more potent up front, to what extent could this actually work against the number of pens awarded e.g. Kyogo more alert and gets the ball in the net without a challenge whilst, say Dessers, a bit slower and contact occurs giving ref a decision. Suspect not as greater number Of goals scored is not huge. Is it worth looking at goals conceded too in the pens conceded calls?
Thanks as ever for the excellent work.
How did you manage to get a record of the touches of each team inside the box?
A couple of questions – do you have the info to compare European games vs domestic?
Is there any value in checking the COVID season, once the league has been won are the games still managed the same way, without such a need for points?
Touches in box are on FotMob (Opta) – i was given a Wyscout scrape for prior years to this
Yes the European trends are as you’d expect ie no patterns or particular differences in how Celtic and TRFC are ref’d
Looking at one season dilutes the sample size
Despite all the work that you have obviously put in to your analysis, I fear that, within Scotland, it will not be taken seriously. The argument will be made that “it’s just some Celtic fan going off on one”.
Out with Scotland it will unfortunately, attract no interest whatsoever.
As I see it, the work you have done is a scientific endeavour and should be treated as such. Football is a multi-billion dollar business world-wide and as such is susceptible to influences culturally, politically, and financially.
An analysis of “patterns of assistance” would be of great interest to a wider audience.
Your analyses, despite being from our wee league, can be generalised from the particular to the universal, perhaps aiding overall Refereeing standards.
Perhaps a technical article could appear in something like the Journal of Sports Analytics and give your work a much wider audience.
You have fashioned a small snowball. Maybe it’s time to roll it downhill and see how big it gets.
Hi Alan brilliant work drawing our attention to this. It simply confirms what we’ve seen with your ‘honest mistakes’ with the Yorkshire whistler. We can only hope our club and others try and force change with the powers that be. It would be fascinating though to see what the penalty stats would have been if the Yorkshire whistler’s decisions had been followed. Quite a difference I suspect!
Great stuff once again Alan.
Wee comparison
I can’t think of any other Celtic defender who scored many many goals, Billy McNeill only scored +37 in 789 games, so
Tommy Gemmell
Played 434. Goals 69 no idea how many penalties
TavPen (stats for The Rangers only)
Played 450. Goals 121 (65 penalties) (82 penalties taken)
His non penalty goals is quite good, tho I wonder how many are from dead ball free kicks !!! Which they are also very good at getting from the refs…
Regards
Peter
One small point Alan. Touches in the opponents box is one thing, “entries into” or “getting into” or (in your graph titles) “possessions [in]” the opponents box are three ways of describing something else. A player or players can and frequently do enter the box (with or without the ball joining them) without any of them touching the ball, and these “entries” aren’t covered at all by these statistics. Also, and of greater relevance, in a single episode of play where the ball enters the box, there can be multiple touches in the box by attacking players, all of which appear to belong to a single “entry” as I understand your use of the word.
If we assume (this is a pure guess) an average of three touches by attacking players on each entry to the box, The Rangers get on average one penalty for every 49 entries to the box, not 147.
If we assume that “average touches per entry” is the same for each team the statistical analysis isn’t changed by your choice of words, but I’m sure you’ll agree that it’s best to use precise language (basically, sticking to “touches” rather than “entries” etc) to avoid potential confusion for good-faith readers, or to provide ammunition for hand-waving by bad-faith ones.
Great work by the way, keep it up.
Neil – the wonderful world of data definitions, something i DO know a lot about!
You raise a fair challenge. The “Touches in Opposition Box” metric comes from FotMob which is Opta. Opta define a “Touches” as “A sum of all events where a player touches the ball, so excludes things like Aerial lost or Challenge lost.”. I also capture this data and label it the same and try and adhere to the Opta definition. I got a data scrape from Wyscout from a friend for the years before this season as FotMob have only started reporting it for the SPFL this season. I Think from memory Wyscout called it “Entries into the box” and i have perhaps not been consistent in labelling. To your question, as the metric is at player level and the team metric is the aggregation of player totals, then each players touch in the box (e.g. a sequence of passes) would count as a unique event. But i accept your point as we are not short of bad-faith critics.