HMMT — 9-Person Poker Tournament 4 Rounds Partition
2050SpecialistCombinatoricsCounting Principles
13th Annual Harvard-MIT Mathematics Tournament
Danielle Bellatrix Robinson is organizing a poker tournament with 9 people. The tournament will have 4 rounds, and in each round the 9 players are split into 3 groups of 3. During the tournament, each player plays every other player exactly once. How many different ways can Danielle divide the 9 people into three groups in each round to satisfy these requirements?