I watched a great interview with Hulk Hogan a while back in which he described the rigging process... The performers know who is going to win in the end, and they may discuss the overall arc beforehand, like Guy A is going to be winning, then Guy B is going to come back for a while, then guy A is going to do his signature move and then Guy B is going to lose. Everything else is ad-libbed, and that's what makes them a good performer or not- the better wrestlers were the ones who could really work the crowd and put on a good show. It's unscripted, but the overall ending is definitely planned. I think it's exactly the same for all sports. They aren't scripted minute-for-minute, and there is a lot of room in there for improvisation, but the winner of the game is known beforehand. Think about how much money is involved.... the marketing, endorsements, ticket sales, all the people who work at the stadiums, food and drink sales, security, and of course all the money that is placed on bets in Vegas. They wouldn't leave a billion dollar industry up to chance.