Why are World Cup underdogs doing so well?

Cape Verde goalkeeper Vozinha was named man of the match in the goalless draw with Spain [Getty Images]This 48-team World Cup has produced some intriguing match-ups and several impressive performances by lower-ranked sides against the world's top teams. Cape Verde, Curacao, Ghana and South Africa - ranked 64th, 81st, 65th and 54th respectively - have taken points from Spain (3rd), Ecuador (29th), England (4th) and South Korea (28th) so far.Are these early tournament surprises a matter of luck, o