Believe you can and you're halfway there Theodore Roosevelt
The only reason why we should be allowed to call Belgium the "Dark Horses" has to be their lack of pedigree in the World Stage. Or a better reason could be our unending craving for a superlative narrative. Otherwise what's the logic? Ok, agreed they were never considered as the main contender by many pundits. Then that's precisely due to their uncanny ability to overlook hard core facts. These are the same pundits who used to pip "England" as firm favourites every World cup only to be left wondering what went wrong! Belgium currently lies in 12th position in the FIFA Ranking, one below England and two below Greece. Then that count for nothing as there is no other European squad which has quality spread across all the position like Belgium has. At least in terms of squad strength, Belgium is miles ahead of England and Greece. One look into final squad announced by Marc Wilmots, you all will understand I am placing them as a Genuine contender rather than a "Dark Horse".
