Football: Curious questions - payoffs

Sometimes there are rumors about players being paid off to miss a penalty or something. When I look at Baggio's penalty miss in 94, I can't help but think he was paid off. I just don't know, he seemed to have much more quality than just kicking a ball straight over a goal. He didn't even follow through like normal, and his hands at his hips.

Also sometimes a good goalie makes a big blunder.. also what about that penalty Beckham missed by a mile?

How would this be done, since you can't count on a game going to penalties, how can you have an agreement beforehand? and how often do you guys think games are paid off?