Sorry for not giving you any answer for your question. I never think about it, and never tried to find out about it. Let wait for someone’s other helpful answer. I will also wait for a proper answer on your question.
I have not such kind of idea i think only admin can describe it or any other member who have information about it.
WELL ! Every gambler know that there is a house edge, by which Casinos are earning. But, how much house edge is…no body can guess it easily. And no any casino want to reveal this secret for their customers.