Every player who appears at an international tournament is credited back to the clubs they've played for. Add it up and you get a league table of clubs, and of countries, ranked by the tournament performance of their current and former players.
Two things to know: a club's country is the country of its league (Monaco → France, Cardiff → England), and players earn full credit at their current club and reduced credit at former ones, weighted by how long they were there.
Pick any of 18 tournaments — World Cup, Euros, Copa América, AFCON, Gold Cup, Asian Cup — drill into a club to see its players, and tweak the scoring weights live.
Why do English clubs dominate? The Premier League has the broadest global footprint — most international players have spent time at an English club, so those clubs collect the most credit. That's the finding, not a bug.
Why is Japan (or Qatar) in Copa América? Copa América and the Gold Cup invite guest nations to fill out the bracket.
Why is a player credited to a club he left? Former clubs still earn credit — at a reduced weight — for the players they developed or held. Tune it with the "Former" slider.
What does "country" mean? The country of the club's league, not the player's nationality — so Monaco counts as France, Cardiff as England.
Where's the data from? API-Football and Wikidata. Calendar-year leagues (MLS, J-League, Scandinavia) map imperfectly to an August–July season.