I love this visualization– gorgeous and subtle. But what of the model?
The population/GDP thing is basically a way to measure a country’s resources. It’s got nothing to do with soccer per se; you could use a similar model to estimate the number of Olympic medals a country will win, for example.
But check the massive fudge factor! The writeup says that the model uses “mostly economic data,” but the coefficient for “experience” dwarfs population and GDP. What does that mean, exactly? Consider Group E. The Netherlands are slightly wealthier than Japan, but Japan has over seven times the population. Yet the Oranje are projected to do much better, clearly because of “experience.” Now that is consistent with what the typical soccer fan would expect in a match between those countries. But compare that to Group D. Germany have about 10x the population of Serbia and around 7x the per-capita GDP. Yet Serbia are projected to win the group, which is opposite the conventional wisdom. So clearly Serbia are a powerhouse in the “experience” department.
From the knockout round projections, we can deduce that Serbia is second only to Brazil in experience. Argentina is way down near the bottom with 14% of Brazil’s experience. I’m scratching my head to arrive at a definition that meets those criteria.
Finally, if you subtract out the population and GDP components from the knockout round projections, you only change the outcome of one match: England-Germany, which is a statistical tie either way. Presenting these projections as “based on mostly economic data” is pretty misleading.