very difficult to get 4 numbers correctly, I've often tried this game but never get a win. gamble is base on luck can't be calculated by percentage 
That's true... All of these "strategies" across the internet but what you said is what it ultimately boils down to. Casinos are designed to make money. The house will always win in the end. The trick is to pull out with your profits before the end. How do you know when that is? It's simple, don't get greedy!