The abstract does say

> limitations, principally the small number of tournaments available for validation and the risk of in-sample weight selection

But I agree this model is no more valuable than Paul the Octopus.

No good AI would cherry-pick data to this extent. Only people are capable of that

It predicts likely winners based on the round of 32 performance (plus prior data). That's still "prospective" with respect to the finals

The baseline matters here: favorites win World Cups all the time. How often would "always pick the two pre-tournament favorites" have gotten the champion in these same 10 tournaments? Without that comparison, 10/10 tells us basically nothing.

It's quite unlikely soccer is one of the few sports without a doping problem and with only very few cases where the referee was paid off.

Since ancient times in Rome where they said "bread and games" are needed to keep the commoners happy, many generations of rulers had time to optimize large-scale sports events.

My personal theory is that these kind of extremely unfair decisions in soccer are a net benefit to stability of society, and there's no incentive for the leadership to aim for full fairness in sports.

Hear me out: When a team loses in unfair manner due to bad decisions of the referee, large masses of people feel the psychological pain of being robbed of a win. This feeling of "unfairness" makes the masses more resilient to experiencing "unfairness" in their day-to-day life, for example when a billionaire is not prosecuted in the same way than a common person.

If we turn the logic around and assume that soccer would always be perfectly fair, then the masses would demand the same kind of fairness also in their day-to-day lives. Obviously this demand for fairness is not aligned with an establishment class that wants to extract the maximum value possible from their citizens, and push as far as they can without risking stability of the country.

From an establishment perspective, it makes a lot of sense to condition the masses for "unfairness", and sports is the perfect way to do it. I'm not saying that the individual referees are paid off to let a certain country win, just that the establishment who runs each country (and thereby also run international sports organizations like FIFA) have no incentive to actually create total fairness.

This might also explain issues like the IOC re-instating russia for olympic games, even though they have not retreated from Ukrainian territory yet. It triggers people who strongly feel about morals and ethics, and it brings the point home that the world is unfair and it makes no sense to push for fairness in the greater context.

The benefit is psychological conditioning for people to accept unfairness.