# How do they trust "digital" slot machines? **URL:** \ **Category:** Factual Questions\ **Created:** [July 23, 2014, 1:55am UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806 "2014-07-23T01:55:46Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [July 23, 2014, 2:32pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/21 "2014-07-23T14:32:31Z")
> [@Cheesesteak](#): > > The house doesn’t have deeper pockets than “everyone”. Not if you add together the pockets of everybody walking into the casino to play over the course of a day/month/year. > > Let’s take a small example. One slot machine with even odds. Joe sits down with $100 and plays. If he busts, the house didn’t “win” because Jeff is going to sit down with another $100 and play. If Jeff busts, or gets bored, then Jimmy is going to sit down with another $100 and play. > > Statistically, if the odds are even, over the course of a day, even if there are 50 different people sitting down to play, it will pay out as much as it took in. That’s what statistically even means. If one person loses money another person will gain, and not every gambler is a completely degenerate gambling addict, people DO walk away when they’re up, to do things like eat, poop, sleep, go home, or just say “I’m gonna buy a TV with this $500 I won”. > > There is a well known statement about gambling. No betting system can turn negative expected value bets into a positive EV total. A corollary for you would be that no betting system (like gamblers busting) can turn even EV bets into negative EV totals. Casinos win because every single bet they offer is negative EV Right on! You cannot turn a negative (or zero) into a positive one by any betting scheme and it doesn’t matter if you or the opponent chooses the strategy. At least no finite strategy. ---
**Author:** ![Ornery\_Bob](https://avatars.discourse-cdn.com/v4/letter/o/da6949/32.png) [@Ornery\_Bob](https://boards.straightdope.com/u/Ornery_Bob)\ **Post date:** [July 23, 2014, 3:11pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/22 "2014-07-23T15:11:56Z")
As for slot machine payouts, you have to remember that the house isn’t gambling, they know they’re going to win and so the only question is finding the payout level that maximizes profits but pays out enough to keep the customers coming back for more. It obviously works at a very basic level. We put in a dollar and “win” nine dollars and all we think about is the win, not that you’ve already put in ten dollars before you got that “winner.” So the point for the casino is to keep those “wins” coming at a regular pace that keeps you going until you’re out of money. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [July 23, 2014, 3:37pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/23 "2014-07-23T15:37:18Z")
In the UK fruit machines have to tell you what the average payout is; it varies between 70 - 85% IIRC. Even though you may argue that would make me a fool to play such games, I do (or used to) from time to time, because the UK-style ones are more of a game. They give you the illusion at least of playing something like an electronic board game, which can be entertaining for a few minutes. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [July 23, 2014, 4:29pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/24 "2014-07-23T16:29:48Z")
> [@bob\_2](#): > > Maybe not in the Good Ole US of A, but in most of Europe, the casinos do perfectly well with one zero. Yeah, there’s plenty of them out there. But all the ones I’ve seen were outside the US. Worldwide, they’re not rare at all. They may even be more common. ---
**Author:** ![dzeiger](https://avatars.discourse-cdn.com/v4/letter/d/46a35a/32.png) [@dzeiger](https://boards.straightdope.com/u/dzeiger)\ **Post date:** [July 23, 2014, 4:47pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/25 "2014-07-23T16:47:01Z")
> [@Mijin](#): > > In the UK fruit machines have to tell you what the average payout is; it varies between 70 - 85% IIRC. > > Even though you may argue that would make me a fool to play such games, I do (or used to) from time to time, because the UK-style ones are more of a game. They give you the illusion at least of playing something like an electronic board game, which can be entertaining for a few minutes. A lot of the US ones are going that way as well. I’ve seen a Clue (UK Cluedo) slot game where there actually was some elimination-based process in the bonus games. That was also the first one I saw where you created a username/password in order for the game to do Xbox-style Achievements, which provide no actual value but no doubt encourage at least some people to play more. I’ve also seen a game hunter themed machine where the bonus rounds had a choice between normal random spin stuff, or actually taking one of the connected light guns and trying to shoot the moving targets on the screen. Probably a demographic shift. As the people with the disposable incomes to go to a casino start coming more and more from gaming backgrounds, the more they’ll look like video games. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [July 23, 2014, 5:24pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/26 "2014-07-23T17:24:58Z")
> [@Mijin](#): > > In the UK fruit machines have to tell you what the average payout is; it varies between 70 - 85% IIRC. In the US, it varies by state. Here in Illinois, they are required to publish their payouts. For example, [here are a bunch of payout tables](http://www.winning-slots.net/casino-payouts.php) across various states. Typically, cheap penny slots have lower payouts than the high stakes slots. It’s typically around 90% for the cheap slots, and up to the high 90s for the expensive slots. ETA: That’s in casinos. I have no idea what the typical payout rate is for slots that you might find at a bar (which only was recently made legal here in Illinois.) ---
**Author:** ![SmartAlecCat](https://avatars.discourse-cdn.com/v4/letter/s/67e7ee/32.png) [@SmartAlecCat](https://boards.straightdope.com/u/SmartAlecCat)\ **Post date:** [July 23, 2014, 5:33pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/27 "2014-07-23T17:33:05Z")
> [@jtur88](#): > > I have had lengthy arguments with people about this. The point is that even if it paid out statistically even odds, the house would still win because the house has deep enough pockets to outlast you, and eventually drives everyone out of the game. This reminds me of the problem of the society that wants boys. If each child has a 50% chance of being a boy, and everyone wants a boy, so they keep having kids only until they have a boy. (If they first have a boy, they have no more kids.) What will be the eventual, steady state distribution in the society? 50% boys It doesn’t matter how long you play, or how long you outlast anyone. If the odds say you win 50% of the time, you will eventually win 50% of the time. You need to go back to the folks you had lengthy arguments with and concede that they were right. ---
**Author:** ![Walton\_Firm](https://avatars.discourse-cdn.com/v4/letter/w/45deac/32.png) [@Walton\_Firm](https://boards.straightdope.com/u/Walton_Firm)\ **Post date:** [July 23, 2014, 5:49pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/28 "2014-07-23T17:49:45Z")
And even when the bells go ringing and the word **JACKPOT!!!** is flashing on the screen for all to see, the casino may still decide to tell you that there was a software bug and you [haven’t actually won anything.](http://www.ibtimes.com/behar-merlaku-wins-57m-jackpot-casino-claims-software-error-382782) Happens more often, apparently. In this case the casino did eventually agree to pay the guy a cool €1million, but that was still only a small fraction of the amount which the machine told him he’d won. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [July 23, 2014, 6:07pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/29 "2014-07-23T18:07:30Z")
> [@SmartAlecCat](#): > > This reminds me of the problem of the society that wants boys. If each child has a 50% chance of being a boy, and everyone wants a boy, so they keep having kids only until they have a boy. (If they first have a boy, they have no more kids.) What will be the eventual, steady state distribution in the society? > > 50% boys > > It doesn’t matter how long you play, or how long you outlast anyone. If the odds say you win 50% of the time, you will eventually win 50% of the time. How does that work? In your example, 50% of the population will have one boy, 25% will have one girl and one boy, 12.5% will have two girls and one boy, and so on. Even taking into account the small percentage of people who have five girls (I have five daughters!) or more, won’t they still be outnumbered by the boys? ---
**Author:** ![Walton\_Firm](https://avatars.discourse-cdn.com/v4/letter/w/45deac/32.png) [@Walton\_Firm](https://boards.straightdope.com/u/Walton_Firm)\ **Post date:** [July 23, 2014, 6:13pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/30 "2014-07-23T18:13:43Z")
> [@Alessan](#): > > How does that work? In your example, 50% of the population will have one boy, 25% will have one girl and one boy, 12.5% will have two girls and one boy, and so on. Even taking into account the small percentage of people who have five girls (I have five daughters!) or more, won’t they still be outnumbered by the boys? No. There isn’t any family with more than one boy (discounting twins and contraception failures), but in a large enough population you may encounter families with 20 or more girls. If you work through the math, you will see that the average family has one girl and one boy - the families with only boys are exactly balanced out by the families with multiple girls. ---
**Author:** ![JerrySTL](https://avatars.discourse-cdn.com/v4/letter/j/e274bd/32.png) [@JerrySTL](https://boards.straightdope.com/u/JerrySTL)\ **Post date:** [July 23, 2014, 6:14pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/31 "2014-07-23T18:14:19Z")
I have a buddy who worked IT on slot machines recently. He claims that whether or not you will win is set before you hit the button or pull the lever on a digital machine. However it isn’t like someone is watching you through the various cameras and make an individual machine win or lose. ---
**Author:** ![chappachula](https://avatars.discourse-cdn.com/v4/letter/c/d2c977/32.png) [@chappachula](https://boards.straightdope.com/u/chappachula)\ **Post date:** [July 23, 2014, 6:18pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/32 "2014-07-23T18:18:20Z")
> [@Artemis\_Tardis](#): > > How do they trust slot machines ? Us Dopers are over-thinking this. Sure there may be government regulation, and engineering analysis of chips, etc, etc,etc. All of which is designed to make sure the the machines take only 1% or 5% profit, etc… And us Dopers then go on to calculate the odds, point out why it’s illogical, etc, etc… But there is a much simpler answer: People who play the machines trust them because they physically see the winners.Lots of winners. An individual sitting at the machine (like the clicheed blue-haired grandmother) does not care if the house keeps a huge chunk of her money: The only thing she cares about is that during the past half hour she has seen other people winning 100’s or 1000’s of dollars. So she has absolute trust that _somebody_ is going to win— and she could be the next somebody. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [July 23, 2014, 6:26pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/33 "2014-07-23T18:26:00Z")
I had to work it out manually, but **SmartAlecCat** is right. Let’s take 8 random families: 4 will have boys first and stop. Two will have a girl first and then a boy and stop. The last two have two girls each, and for the third child, one has a boy and one has a girl. Grand total: 8 boys, 7 girls. You might think that’s not even, but try it again with 16 families: 8 have boys first. 4 have girls first, then a boy. 2 have two girls and then a boy. Last two: one has three girls and a boy, the other has four girls. Grand total: 16 boys, 15 girls As you scale up, there will always be one extra boy, but the ratio will get as close to 50% as you want. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [July 23, 2014, 6:29pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/34 "2014-07-23T18:29:26Z")
> [@chappachula](#): > > Us Dopers are over-thinking this. > … > But there is a much simpler answer: > People who play the machines trust them because they physically see the winners.Lots of winners. I confess. You are totally correct. I too lost the forest for the trees. Thank you for the correction. ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [July 23, 2014, 6:39pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/35 "2014-07-23T18:39:49Z")
> [@Keeve](#): > > Let’s take 8 random families: 4 will have boys first and stop. Two will have a girl first and then a boy and stop. The last two have two girls each, and for the third child, one has a boy and one has a girl. Grand total: 8 boys, 7 girls. I count 7 boys and 7 girls there. > [@Keeve](#): > > You might think that’s not even, but try it again with 16 families: > 8 have boys first. > 4 have girls first, then a boy. > 2 have two girls and then a boy. > Last two: one has three girls and a boy, the other has four girls. > Grand total: 16 boys, 15 girls I think that’s 15 boys and 15 girls. ---
**Author:** ![SmartAlecCat](https://avatars.discourse-cdn.com/v4/letter/s/67e7ee/32.png) [@SmartAlecCat](https://boards.straightdope.com/u/SmartAlecCat)\ **Post date:** [July 23, 2014, 6:48pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/36 "2014-07-23T18:48:56Z")
And the same math works for slot machines – if the odds say the house will win 50%, the house will win 50%, regardless of how many people always blow their entire stash or how many walk away. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [July 23, 2014, 7:20pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/37 "2014-07-23T19:20:18Z")
> [@Giles](#): > > I count 7 boys and 7 girls there. > I think that’s 15 boys and 15 girls. I am SO busted! :eek: I had to count the girls because it got so complicated. But I figured every family has exactly one boy, so I didn’t bother to count. :smack::smack::smack: ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [July 24, 2014, 1:36pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/38 "2014-07-24T13:36:41Z")
> [@Hari\_Seldon](#): > > Right on! You cannot turn a negative (or zero) into a positive one by any betting scheme and it doesn’t matter if you or the opponent chooses the strategy. At least no finite strategy. Mea culpa, mea maxima culpa. I was wrong and the deep pockets argument is correct. The easiest way to see it is to reduce it to the simplest case that you have one chip and the house has two. Let p denote the probability that the house wins and then 1-p is the probability you win. The first roll will either break you (half the time) or reduce the house to where you were when you started (the other half the time). So p = 1/2 + (1/2)\*(1-p) which solves immediately to p = 2/3. If you want to explore this at greater length (which I did not), let p(n,m) denote the probability that the house wins if the house starts with n chips and you with m. The relevant equations are that p(n,m) + p(m,n) = 1 (so that p(n,n) = 1/2 as you expect) p(n,0) = 1 for n \> 0 (p(0,0) is undefined) p(n,m) = (1/2)\*p(n+1,m-1) + (1/2)\*p(n-1,m+1) ---
**Author:** ![SmartAlecCat](https://avatars.discourse-cdn.com/v4/letter/s/67e7ee/32.png) [@SmartAlecCat](https://boards.straightdope.com/u/SmartAlecCat)\ **Post date:** [July 24, 2014, 1:52pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/39 "2014-07-24T13:52:53Z")
> [@Hari\_Seldon](#): > > I was wrong and the deep pockets argument is correct. Deep pockets don’t matter – if the odds are that you win 50% of the time, you will win 50% of the time. Every bet is independent. It doesn’t matter how long you play, or when you walk away. ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [July 24, 2014, 1:58pm UTC](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806/40 "2014-07-24T13:58:44Z")
Hari, the deep pockets argument is irrelevant because the players, as a group, have more than enough money to be considered a deep pocket. No casino is going to bust all of the players that walk through their doors, certainly not in an level-odds scenario. There are far too many bets for a level-odds system to swing far enough to bust everyone, the chances of that happening are incomprehensibly small. [Previous page](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806.md?page=1) [Next page](https://boards.straightdope.com/t/how-do-they-trust-digital-slot-machines/693806.md?page=3)