Suppose two MMA gyms (teams A and B) compete in a league tournament each month. The tournaments are made up of fighters from many gyms, but each month one fighter from team A fights one fighter from team B. There is no end in sight for the monthly tournaments. The winning fighter (team) receives $6,000, the losing fighter (team) receives $0. They (against the contract with league) discuss colluding to split the $6,000 prize money each month for these specific fights, each getting $3,000. If one cheats, the other will fight hard forever (grim trigger) leaving each with an expected payoff of $2,000 due to injury expenses