The Social Golfer Problem (SGP) is a combinatorial optimisation problem. The task is to schedule

After the original SGP instance was first posted to the discussion group

Whether there exists a solution for 10 weeks was an open question for several years, until Alejandro Aguado constructed an explicit solution for theProof: Suppose w>=11, and observe the schedule of an arbitrary but fixed player α. Each week, α plays in a group with 3distinctother players. To play for 11 weeks, α would have to partner 3 × 11 > 31 other players.