A friend of mine is convinced this happens quite often in MMA. I think it may happen but not with main card guys. Not talking about the brass giving orders and making it WWE stuff. But one fighter going into a bout and taking a dive...perhaps because he put money on himself to do so and would make far more than he would winning.
Not trolling but opening up conversation on what I feel is an interesting topic. The sport of boxing has been known to have guys dive.