I won't say leagues have NEVER bribed/instructed officials to try to help a team win. This with officials has been documented in the NBA.

Pro players make so much money, and make much more if they play very well, they never (or very close to never) throw a game or even shave points. I think at times officials are instructed to favor a team, but not in most games-- so it's closer to "fair and balanced" than "WWE." I'd bet everything I own, if the truth were to be revealed, that in at least 99% of games in major professional sports (MLB,NFL,NBA,NHL) all players are trying to win. I do say players; that doesn't mean officials are always trying to be fair.

What I think is underestimated though, given that college athletes in theory make no money beyond their scholarships, and since what money they're secretly paid is clandestine, make a lot less money than pro athletes, is that I think a lot of college athletes have a much lower price than a pro athlete does to shave points and even possibly throw games on occasion. I think college sports are probably not as clean as pro sports. However, top college players still want to get pro careers and make big money there, so college sports are probably mostly on the up and up-- but if you're looking for fixed games you'd find many more in college sports than pro sports.