Welcome back Enfuego, good to see you. When I saw this thread, I just assumed it was an old thread.
I think it takes three things to fix games. One, someone not making a ton of money and two, a sport where one man can be paid to make a difference and three, a sport that has a lot of action.
In the old days, there were many more opportunities. Like the Chicago Black Sox. A lot fewer opportunities today.
Most likely to be fixed?
Soccer, by buying the referee. Like what happened to Italy in the World Cup in Korea just a few championships ago. Although video review has mitigated that to some degree
And college sports
With technology today, I think it's pretty easy for the house to see suspicious patterns, so I don't think widespread fixing is an issue