Crazy run by this gamblers, but sooner or later casinos will have to stop them. Their method? Change the dealer to disrupt everything, you can hear it that the gamblers wanted that dealer back but they say that he will just take a break.
And obviously the new dealer will have different throws and so they stop this gamblers from continuing their winning streak.

This is roulette by the way, I have this kind of experience, not that I'm winning big, but I have played before wherein me and my buddies are in a streak then suddenly they've change the lady dealer and so after that, we lost after one spin with the new dealer and I told them that we better stop and take the profits and that's what we did.
I'm not at all sure that a casino employee has any influence on the throws, even though the Internet is full of all sorts of stories about how they learn to throw perfectly every day, and this feeling becomes literally professional for them. But it seems to me that a spinning roulette wheel is still too complicated a mechanism for the ball to hit certain numbers due to skillful throwing, and therefore I attribute it more to superstition.
And even my ex-girlfriend, who works at an online casino, told me that it was impossible to do this, although for some reason players often blame casino employees for either affecting their throws in some way, or they can throw the ball very badly to those they don't like.