Of course this is all guessing since there isn't an official number, but I think we can be somewhat accurate if a lot of people from around the world contribute that know their stuff. There was a recent article (can't find it now) that states that the US has 4 milllions male youth soccer players. What are your estimates for countries like Brazil, England, France, Mexico, Japan, Korea, Germany, Argentina, Italy, Spain, China...etc? Comparing the player pool, I think we can deduct which country will be successful in the future...