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# Do slot machines remove outcomes after they're chosen?

9 May 2009

Hi John,

I would like to to thank you for your no-nonsense attitude to answering questions. I have two simple questions.

First, when the slot chooses a particular outcome for display, is this choice removed the pool of future choices until all choices have been played and the machine has to start a new cycle of all available choices? I know it randomly goes and chooses what will be displayed, but I am curious if the pool of choices diminishes as choices are displayed. Or are all the possible outcomes eligible for selection each and every turn?

Secondly, does it change the outcome if you choose to play a X10 bet versus a X1 bet? The reason I ask is because a machine could get clobbered by someone who is lucky enough to keep betting X1 and then every once in a while X10 and hitting decent jackpots?

Shannon

Dear Shannon,

Thanks for the kind words about my columns.

To answer your first question, all outcomes are possible on each and every spin. Outcomes are not removed from the pool as they are chosen.

Slot machines are like roulette wheels. On a roulette wheel, the ball can land in any number's pocket on any spin because the pockets aren't removed from the wheel once the ball lands in them. This is known mathematically as random sampling with replacement, although the name is a bit confusing in the cases of the roulette wheel and slot machines because we're not really putting what was selected back in the pool. More accurately, we're just not removing what was chosen.

Contrast this situation with blackjack. As cards are dealt, they're put in the discard tray, not back in the shoe from which the dealer is dealing. Those cards won't be available again until the dealer shuffles up. This procedure is known as Random Sampling without Replacement.

You might hear slot directors or salesmen talking about cycles. They might say that one machine hits the jackpot six times per cycle while another hits its jackpot eight times. In their lingo, a cycle is just the pool of outcomes possible on a machine. It doesn't mean that the slot program actually goes sequentially through a defined cycle of outcomes.

One more thing about outcomes: Not only is every outcome possible on every spin, every outcome has the same probability of landing on the payline on every spin.

As for your second question, the only way players could clobber a machine by changing between betting the minimum and the maximum is if they knew before making their bets whether the spin would be a winner or a loser. Without that knowledge, players are just as likely to have a losing spin at the maximum bet as they are at the minimum bet. It would take a great deal of luck to time the bet changes just right to really clobber a machine.

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.

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