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12 December 2005

I have read that every spin on a slot machine is totally random and that it is theoretically possible to win a jackpot twice in a row or lose 1,000 times in a row. How could this be possible if the computer chips are programmed to pay back a certain percentage over a year, 90% for example?

If there is such a thing as a payout cycle then how could each spin be totally random? It simply is not possible. If you throw dice over a long period of time, you would never be able to get the dice to come out a certain way, on average.

If all slot machines were in fact totally random, then there would be absolutely nothing you could do to improve your odds.

Thank you,
Kevin

Dear Kevin,

Let's look at each one of your statements:

Every spin on a slot machine is totally random. True.

It is theoretically possible to win a jackpot twice in a row. True.

Or lose 1,000 times in a row. Theoretically possible, but the probability of it happening is so low as to be nearly impossible.

Computer chips are programmed to pay back a certain percentage over a year. This is not true. The machines are programmed to chose an outcome at random from a population of outcomes. The population is set up such that the number of ways to make the winning combinations and the amounts they pay as compared with the total number of combinations possible returns a particular percentage to the players. Machines are not programmed to pay back a certain percent over a year, or any other period time.

If there is such a thing as a payout cycle. There isn't. If a machine has just hit a number of times for you, you can say it's in a hot cycle. But the cycle exists only in the past and only as your observation. The machine is still choosing outcomes at random. A fair coin toss can just have resulted in heads three times in a row and you could say the coin is in a heads cycle. The probability of tossing another heads is still 0.50, though. There's nothing in the coin influencing it to either continue or break the cycle.

If you throw dice over a long period of time, you would never be able to get the dice to come out a certain way, on average. Not true. If the dice are fair, there's no way to know what number will be thrown next. But if you record the numbers thrown over a long period of time, I guarantee you that you will end up with the Pyramid of Craps.

If all slot machines were in fact totally random. They are. ...Then there would be absolutely nothing you could do to improve your odds. I agree with what I think you mean, but not with the way you said it. It depends on what you mean by "odds." If you're playing a Buy-a-Pay or a multi-line machine, you can improve your hit frequency by playing more coins or more lines. If you're playing a Bonus Multiplier, you can increase your long-term payback by playing max coins. Note that these actions may not decrease your expected loss per spin.

What I think you mean is that there's nothing you can do to influence the symbols that land on the payline. That's absolutely true.

Best of luck in and out of the casinos,
John

Your articles all seem to indicate the casinos do not or cannot change the hit frequency of machines simply by inserting a new chip in the machine. This being the case how do you explain the banks of machines used in slot tournaments? In a tournament the machines seem to hit a lot more frequently than when the same machines are not involved in a tournament.

Perhaps you're confusing my articles with someone else's. The only way to change the hit frequency or long-term payback on a machine is by putting a new chip with a different virtual reel layout in the machine.

Tournament chips have slightly different playing characteristics (free, timed play versus paid play) and vastly different virtual reel layouts. Hit frequencies might be as high as 99% and long-term paybacks in the thousands, if not even higher.

Best of luck in and out of the casinos,
John

Wanted to get your opinion on slot issue.

I watched a series of programs on the Travel Channel this weekend that dealt with Las Vegas gaming. Was a very good series of programs with some excellent tips by the "experts," including Frank Scoblete. What really got my attention though was a statement made by a former employee of the Nevada Gaming Control Board whose job it was to try any way possible to cheat at the slot machines.

He did discover a way, used the system and beat the slots every time. Of course, he was caught and fired and sent to prison, etc. Anyway, he said that while working on the machines he discovered that it's impossible for a computer to generate a random number, only a series of numbers over a period of time that continually repeat, and he used that to beat the machines. In other words, and he said this was something that no one really wanted to get out and be known, but there is no random number generator.

Thank you,
Ted

Dear Ted,

My first thought is, "Well, duh!"

My second is, "How come I get over 300 channels from Comcast and The Travel Channel is not one of them?"

Sarcasm aside, you have to take the technical information these mass market programs provide with a grain of salt. Sometimes, they simplify a concept so much that what they say isn't technically true. Other times, I think they just don't understand the concept.

I assume the NGC employee profiled was Ron Harris. His method for cheating the slots was to reprogram them. I wouldn't say that he discovered a way to beat them.

As for computers not being to generate a number truly at random, this is not an earth-shaking revelation. Most RNG use mathematical operations and 2 + 2 always equals 4. The RNGs in slot machines are more correctly called pseudo-random number generators. The stream of numbers they generate satisfy many of the tests for randomness, but they are in fact generated by deterministic functions.

Best of luck in and out of the casinos,
John

John,

I really enjoyed the Odyssey slot machines especially, the ones the video poker and the floating hands. Will the company that bought Silicon Gaming ever rerelease these games? They are fun to play and getting hard to find.

Thanks,
Ryan

Dear Ryan,

I liked Silicon Gaming's machines too. Although short-lived, I think they showed the slot industry how important great graphics, sound and game design were going to be in future slot machines.

IGT bought Silicon Gaming. I doubt we'll ever see any of the old Silicon games rereleased, especially not in the Silicon cabinet.

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 send a reply to every question. Also be advised that it may take several months for your question to appear in my column.

John Robison

John Robison is an expert on slot machines and how to play them. John is a slot and video poker columnist and has written for many of gaming’s leading publications. He holds a master's degree in computer science from the prestigious Stevens Institute of Technology.

You may hear John give his slot and video poker tips live on The Good Times Show, hosted by Rudi Schiffer and Mike Schiffer, which is broadcast from Memphis on KXIQ 1180AM Friday afternoon from from 2PM to 5PM Central Time. John is on the show from 4:30 to 5. You can listen to archives of the show on the web anytime.

#### Books by John Robison:

The Slot Expert's Guide to Playing Slots
John Robison
John Robison is an expert on slot machines and how to play them. John is a slot and video poker columnist and has written for many of gaming’s leading publications. He holds a master's degree in computer science from the prestigious Stevens Institute of Technology.

You may hear John give his slot and video poker tips live on The Good Times Show, hosted by Rudi Schiffer and Mike Schiffer, which is broadcast from Memphis on KXIQ 1180AM Friday afternoon from from 2PM to 5PM Central Time. John is on the show from 4:30 to 5. You can listen to archives of the show on the web anytime.

#### Books by John Robison:

The Slot Expert's Guide to Playing Slots