Manipulating slot machines on a cruise ship

Hi, John,

I noticed in your response to Mike you said "I'm afraid you won't believe me". I have to say even though I work in the industry and I know you are right there are some experiences that make it hard to believe.

I recently took a Carnival Cruise for vacation and being in the industry, it didn't take me long to sniff out the casino. After playing for a while I realized that not only could I not hit some of the small payouts but I also noticed that symbols would rarely even land on the pay line.

This trend continued for the duration of the cruise until the last day at sea. That is when I had some big hits and of course a bunch of the little hits as well. I also noticed a number of other patrons getting big hits as too. And all of this did not start until the last day of the cruise. I have a saying when it comes to gambling. "Just when you THINK you've got it figured out.... stop playing". I know enough to know you never have it figured out, but I must say this is the first time I really thought I could see a trend.

You were right it is hard to believe because you can't help conjuring an image of a seedy character behind closed doors flipping a switch and laughing hysterically as your money flies down the tubes.

Regards,
Jason

Dear Jason,

I'm afraid you won't believe me.... Sorry, just couldn't resist.

If you spend enough time in a casino, you'll see all sorts of things. You'll see times when no machines are hitting, when every machine is hitting, and when results are mixed.

On one of my early trips to Las Vegas, I did very well on machines on a rotating turntable in Circus Circus. Everyone was doing well on those machines that night. I remember seeing many machines with trays nearly filled to the brim with coins. I won almost enough to pay for my trip.

On my next trip, my first gambling stop was at my "personal ATM" at Circus Circus to win back my airfare and hotel costs. This time, none of the machines were hitting and instead of a party atmosphere, it was more like a funeral. Not only did I not win enough to pay for my trip, I didn't win anything at all and left there with less than I walked in with.

With such diametrically opposed situations, it's hard not to believe that there isn't some manipulation involved. But if I watched this group of machines for an extended length of time or had many more periods of short observation, I would see times when the machines were hot, when they were cold, and when they were mixed.

There's no manipulation of the machines. The periods of synchronicity don't disprove randomness. Rather, they are a necessary consequence of randomness.

You have one observation of machine performance on this ship. If you were to take another cruise on the same ship, you might find the opposite occur — machine hitting during the trip, but not on the last day.

As you know, this one observation isn't enough to draw any conclusions about the machines on the ship.

Best of luck in and out of the casinos,
John

I have noticed that you have said the numbers in a video keno machine are selected randomly. There are times though that it seems sets of 20 numbers are being called, or screens are being called. The screens even seem to be called in groups. There are too many times that you will play a block of six numbers and hit five. The very first number in the next game is the missing number from the previous game. This happens too frequently to be random.

You say that the missing number is drawn first in the next game too frequently to be random.

How frequently should this occur if the game were random?

Honestly, I don't know and I don't know how to calculate it.

Sometimes events that we think should be rare occur much more frequently than we expect.

Consider the "duplicate birthday" problem. How many people, chosen at random, do you think you need to be nearly certain (99% sure) that there will be at least one group of two people who share a birthday (month and day, disregarding the year)? Make a guess and then read on for the right answer.

You probably guessed around 250 to 300 people. You might think that we have to go well over half the number of possible dates to be nearly certain there will be a duplicate.

The correct answer, however, is fifty-seven. It takes fewer people than most of us think to get a shared birthday. It happens more frequently than we expect. The only way to know how frequently it should happen is to do the math.

Your situation may be happening as frequently as it should in a truly random process. It's also possible that your situation isn't happening as frequently as you think it is.

Drawing a needed number first on the next play sticks in your mind because it has more meaning to you than drawing an unneeded number. The events that stick in your mind outweigh those that don't and it can seem like they happened much more frequently than they really did. I've been a victim of this misperception myself. It wasn't until I kept careful track with pencil and paper that I realized what I thought was happening very frequently wasn't happening frequently at all.

Best of luck in and out of the casinos,
John

Send your slot and video poker questions to John Robison, Slot Expert, at slotexpert@comcast.net. Because of the volume of mail I receive, I regret that I can't reply to every question.