Before the Confederations Cup I posted this ranking of national teams according to Goalimpact and other metrics. So how did they fare?
Betfair had all games right, just based on the odds of the World Cup (sic!) title. It was not entirely level playing field though, as Brazil's home advantage has been factored in into the odds while the other measures just rank the teams and thus got the final wrong. In all other games of Brazil, they would have been the favorite even without the home advantage.
However, we can still conclude that the cup was without any big surprises and was very predictable unless you use a very defunct scoring system such as the FIFA uses for their world ranking list. However, the market values published at transfermarkt.de are also not a perfect proxy for playing strength. Assuming transfermarkt.de publishes correct estimates of true market values, one must concluded that Mexican players are undervalued or Japanese overvalued.
Anyway, I'm content with Goalimpact's predictions. But the bar was low at this tournament. Everything but the final was right, so would I predict all the same? No! Of course not. Even if the predictions were correct, there is much to learn. Tahiti was rated far too good by Goalimpact and received a hefty downgrade as result of this tournament. This will also lead to a revaluation of historic Games of Tahiti with the new lower value and, in turn, common opponents will also experience a second order downgrade. Mainly this effects OFC countries. On the upside Brazil's performance raised the team's Goalimpact.