The eight third-placed teams with the best record will go through to the last 32.
The tiebreakers start with group points, and then goal difference, goals scored, disciplinary record and finally the Fifa world ranking.
The last 32 fixtures are determined by the precise combination of the groups which provide the eight qualifiers.
We started out with 495 possible outcomes, which will gradually reduce as the groups complete.
And, for instance, if groups B, D, E, F, G, J, K and L provide the third-placed teams, that would also mean Mexico (1A) would play Ecuador (3E).
All remaining combinations for Bosnia-Herzegovina (3B), Sweden (3F) and Paraguay (3D) send these countries to only one group winner.
That means United States v Bosnia, France v Sweden and Germany v Paraguay.