Ask The Wizard #63

Do casinos have the ability to change the slot payout percent (or really take percentage) at any time after receiving the machine? I always thought that was set at the manufacturer and that the RNG was not changeable.

Jarin from San Diego, CA

Physically all you have to do to change the return of the slot machine is change the EPROM chip inside. Assuming the casino manager had all the EPROM chips, which I think they sometimes do, they could make the change themselves. However in a major jurisdiction the change would have to be reported to the gaming authorities, not to mention internal paperwork. The random number generator is constant, it is what the program does with the random numbers that determines the return.

Do you sell t-shirts?


No. I have thought about it but I’m afraid that if I ordered a large quantity I would get stuck with most of them.

First, thanks for the great site. Are you going to review "Draw Caribbean Stud" soon. I will be down in Dubuque this weekend and they have it there. I tried it briefly last time, but had no idea as to perfect strategy so I only played a couple of hands (won ten bucks).

Bradford Wiley from Winthrop Harbor, U.S.

Thanks for the compliment. I just saw the game at the California casino here in Las Vegas, but it wasn’t open yet. I got the rule card and will work on when I have the chance. At this time I have no information about it at all.

What are the odds of a dealer getting 3 blackjacks in a row on a single deck table with two players?

J.A.S. from Las Vegas, USA

It depends whether there is a shuffle between the blackjacks. Assuming there isn’t the probability would be 8*(16/52)*(4/51)*(15/50)*(3/49)*(14/48)*(2/47) = 0.000044011058. The number of other players doesn’t matter, except if they cause a shuffle.

I play 7-stud in a poker room with a bad beat jackpot. The minimum bad beat hand to win the jackpot is four of a kind beat by four of a kind. What would be the probability of this occurring, and how would you go about calculating it?

Bruce from Mahomet, Illinois

The probability of any two specific players both having a four of a kind is (13*COMBIN(12,3)*43*9*COMBIN(41,3)+13*12*11*4*6*10*COMBIN(41,3)+13*12*4*11*COMBIN(41,3))/(COMBIN(52,7)*COMBIN(45,7)) = 0.000003627723. There are combin(7,2)=21 ways to choose 2 players out of 7. Avoiding the case of 3 or more four of a kinds the probability would be 0.000076182184.

I’m thinking of visiting your advertisers’ web sites just to make sure they keep supporting your ability to give free advice to the gambling public. Your site is great. My question: Is it possible to draw the same card that is discarded in video poker? The Michigan Gaming Control Board has given me a half-answer, stating that all events are determined by a random number generator. Secondly, are the chances of hitting paying hands in VP subject to manipulation by the casino, like slot machines that are also governed by a random number generator?

Jack from Detroit, USA

Thanks for your support. I encourage everyone to click through the banners to help support the site. To answer your question, no, it is not possible to get the same card back. The machine represents a fair deal from a single deck. Once you discard a card you can’t get it back. To the answer the second question, no, the casino can not change the probability of each hand. The video poker machines deal a fair game. How often you get each hand depends on the random draw of the cards and your skill in playing them.

In Texas Hold ’em if the flop cards are all the same suit what is the probability any given player will hold two more cards of the same suit?

Dr. Don

There are 10 cards left of the same suit, and 49 left in the deck. So the probability is combin(9,2)/combin(49,2) = 36/1176 = 0.0306.

What are the guidelines for doubling up on winning hands in video poker? If I do double up and the 5 cards show a winning hand, would that have been my next hand had I not doubled up?

Tim from Springfield, IL

The double up feature is truly fair and has no house edge. This is one of the few times I say you can go either way and just do what you want. From what I know of how slots are programmed the cards you get in the double up screen are not what you would have got on the next hand. Random numbers are constantly being drawn and those chosen at the exact moment you hit "deal" determine what cards you get.