Is it possible to reach 100% accuracy in refereeing?

Perfect game / season in refereeing is something referees sometimes talk about, but is it actually possible or is it at all sensible to try to measure it? We have built RefPal to measure the accuracy of refereeing decisions throughout a match, a season and even throughout one’s career. We decided at the beginning that there is no learning benefit in looking into each decision - each throw-in, corner or foul. That would mean too much info and very little learning. Hence we concentrated on the following 3 categories of decisions:

• Penalties
• Red cards (including 2nd YC)
• Yellow cards

Accuracy in Estonia
So now let’s have a look at the last four seasons (36 rounds & 180 games) of Estonian refereeing to see how we have progressed with our accuracy throughout. Each incident in these three categories is uploaded into RefPal and after the referee team and the community (other TOP league referees + observers) have had their say, the referee committee gives their final verdict at the end of each week.

(number of incidents evaluated)
* season 2022 is ongoing with 11 rounds out of 36 officialized

We can see clearly how the decision accuracy has been improving in each of the categories mentioned. That is a great testament to the usefulness of RefPal and moreover we can compare this with the activity of the referees in the system and see that the time spent learning and decision accuracy on the field of play is clearly correlated. We can also dig deeper as each incident is categorized under Topic and Subtopic so for example we could look at:

Topic: Severity of offense and Subtopic “Strike to the head in aerial duel”

* There are over 250 subtopics you can look at separately

When we started measuring the accuracy, one of our first discoveries was that our referees are not doing well enough in offences commited in aerial duels as it is difficult to detect if you are not ready for it - the hand movement is very fast. So we concentrated on this in seminars and also through observation reports. We saw an immediate improvement in the following seasons and by this year we can say that our referees are really great at it.

Accuracy be referee
In RefPal you also have the chance to see the same statistics through the lense of a single referee or compare the performances of all of your referees (visible only to the referee committee). Since the inception of RefPal we have been wondering if it is possible for a referee to be able to come through a season with 100% accuracy in red cards and penalties. There have been referees with perfect results in one but not both of these key categories. That all changed in 2021 when Kristo Külljastinen achieved an amazing result of getting 10/10 decision correct in red-card incidents and 18/18 decisions correct in penalty area incidents out of 16 matches he refereed in Premium League. On top of that his yellow card accuracy was also great at 88% - making him a worthy winner of the “RefPal referee of the year award” in Estonia. Also you can read an interview with Kristo where he explains his success and the ways he has achieved this.