Of course it can be rigged. Gambling is retarded. Why would you even gamble, if not for fun with cents?
You can gamble just for fun. I'm doing it, and it really is fun. There are websites like PrimeDice featuring faucets too, so you're getting free money to play with.
Sports gambling are sometimes rigged by the good thing is you can choose on different sides so if you have a feeling that a certain team will be given the opportunity to win because it is rigged then simply put your bets there.