You have a valid point. In general, the whole Casino betting is pretty tough to strategize if the system is not known already. Since most Casino games could get configured into a game that anyone could learn then win a whole bunch of money it is pretty safe to say that the casino games are usually rigged to be against the average gambler.
Sports Betting is much easier to see if there is any rigging going on because most players have signs that they show when they aren't into the match.
Of course sports betting is easier to predict, but only there is an accurate information about the players, and not rumors on the Internet.