Format and schedule proposals for a FIFA World Cup with 12 four-team groups

After the expansion of the FIFA World Cup from 32 to 48 teams starting from the 2026 edition, the initial proposal was to split the 48 national teams into 16 groups of three. Among other drawbacks, this proposal provides potential for collusion. Recently, after widespread criticism, FIFA officials signaled the possibility to re-discuss that proposal, pointing to a tournament with 12 groups of four teams. If this new proposal prevails, relevant questions arise about tournament design and schedule. In this paper, we propose tournament formats for a World Cup with 12 groups of four teams, considering a number of criteria, such as non-collusion, symmetry in rest days, no dead rubbers, and a tournament length of about one month. At the same time, our proposals attempt to adhere to the traditional format, with some nuances either in the group stage or in the knockout stage