It's a weird thought for anyone to think of having control of each bet they make. Nobody can't control what they don't know the outcome to be; rather, they expect the luck of gambling to be shown to them for their bets win, not by their might. If it's by some people's willpower or control of gambling, I don't think there will be many gamblers who would take gambling as luck-based stuff.
But here, gamblers are trying to engage in responsible gambling, stake on low odds, so they can win little profit that will come together as big profit. People only stake high odds, they know they can lose the money. People cash out before the final game is up. Do you get? All these strategies will not be used by gamblers if we can predict the future.
Anybody that keeps winning, maybe low-odd games or getting high numbers with dice rolling, is lucky. You won't tell me there is a pattern, you throw it, or there is an angle you throw it to, that makes it roll in your favor. So I totally agree with you, you can't predict the outcome of something you don't know. So it's just a little bit fictional to say you can predict the outcome of games or dice roll.