4-4-2
The 4-4-2 system has been the second most frequently used formation in the opening matches of the World Cup, proving that a classic never goes out of fashion, even if its use has declined significantly over the course of the decade.
For international football teams, it offers a very basic set up that all their players are generally well versed in playing in. Given that these sides often have precious little time to get to know one another, that is an important facet for coaches plotting how to make best use of a limited resource.
It is a formation that offers balance all over the park, with a basic four-man defensive structure and two forwards. Of course, the midfield is generally where the variation in this system can take place. Traditionally, two wide attacking players are used, although the set up can be made much more defensive by deploying two more central midfielders.
Sweden nearly used the formation to great success against Germany but as they tired at the end of the game they were caught out. Nevertheless, they maintained their predictable but effective tactics for their following match against Mexico and ran out 3-0 winners, claiming the group in the process.
Senegal, meanwhile, went 4-4-2 when they stunned Poland in their opening match of the competition. When they switched back to their classic 4-3-3 against Japan, they were only able to score a draw and were eventually eliminated by the Asian side on the basis of fair play.