DURBAN, SOUTH AFRICA - JUNE 25: Cristiano Ronaldo of Portugal challenges Gilberto Silva of Brazil during the 2010 FIFA World Cup South Africa Group G match between Portugal and Brazil at Durban Stadium on June 25, 2010 in Durban, South Africa. (Photo by Doug Pensinger/Getty Images)
34 of 48 Group Play matches ended with a win, and the winning teams enjoyed an advantage in most game-level statistics:
The winning teams completed more passes, and though their average possession location wasn't any closer to their opponent's goal than the losing team, they had more offensive zone opportunities. Their percentage of shots taken was slightly higher than this (58% vs 55%) but the key difference was that the winning teams were more likely to put the ball in the net from the same locations as the losing teams. Some of this is because the winning teams really do have better scorers, but a lot of it is simply luck and not sustainable in the long-run, unlike ball possession.