[Bona]

Well, you specified casino so it's a given that you will be dealing with some form of rake, odds shortage or the like. To really expect to double your money you have to get to the "other side of the table" in other words where you have the best of it.

Having said that I'm told the very best black jack players can create a small edge. I know many people create an edge for themselves in poker by being enough better than the other players to cover the rake. In short play a game against other players in which you have a skill edge. Don't play games that are strictly random chance and feature a "cost" or drag. You can manage your bets and bankroll at games like craps, etc because well chosen bets on the layout have a low house percentage. But you will still pay the house over time. Sports betting is not my thing but I can see where highly skilled experts might be able to do well at it. But I expect half educated "weekend" players probably get killed by the vig.

I play poker. With a sufficient bankroll to cover the variance swings. I keep accurate/long term records so I don't kid myself about my relative skill level.