n order not to close the door, the casino will add a number 0 to the roulette, which will become 0 to 36. You can bet on odd number or even number, you can also bet on 0. Your winning rate at this time has quietly reduced from 50% to 48.4%, the winning rate of the casino has become 51.6%. Don't underestimate this 1.6% probability change, which is the secret weapon that the casino can't make stable profits. With this secret weapon, casino will not cheat and is not afraid of your winning. Because when the probability is standing on the casino side, the casino’s winning will be a high probability event, as long as you insist on gambling, the casino will take your money out sooner or later. The luxury decoration of the casino and the professional service plus the considerable annual profit are supported by the advantage of 1.6% probability. What the casino need to do is to increase customer traffic and cash flow because it knows that it is winning.