Fixing of matches is not only done by those that practices, there are organisations that their jobs are to fix matches that is what they do for a living, they fix matches through the following ways.

1. Pribing refs and players

2. Persuading lmportant layers to fail their duties

3. Threaning of a team players

4. Attacking of team of players

This strategy is strictly unofficial and it was the one that FIFA fought against few years ago, did you remember AC Milan, Inter...etc FIFA sees this strategy as criminal offence since since it is not done by the accepted individuals.