[Danny72]

Although the World Cup is the most well known (and watched) soccer tournament, it isn't that representative of soccer.

1. It's mainly a knockout tournament which obviously increases the variance

2. International sides aren't a cohesive team like domestic club sides only playing a handful of times per year leading up to the tournaments.

Compare this to the domestic leagues where the league format reduces the variance and players spend most of the year working with who they're playing with on the pitch. In the EPL, the #1 ranked side going into the season probably wins the league 75% of the time. It's a much lower number though for the domestic cups because of the knockout format.