Like, suppose I won $800 in one spin on the Monkey Madness slot machine (fictional). Is there a way where I could find out that this event had an odds of, say, one in five hundred thousand of happening?
I’m partly assuming here that modern slot machines are outcome based (“this machine has a one in five million chance of giving you the jackpot”) rather than odds based (“the cherry has a 1 in 8 chance of appearing in row 1, column 1, while the bar has a 1 in 100 chance, etc.).
The odds vary around the country and between different “games”. The payout percentage varies between 95.05% at the top and 89.12% (Virginia) at the bottom.
Slot machine odds are some of the worst, ranging from a one-in-5,000 to one-in-about-34-million chance of winning the top prize when using the maximum coin play.
Don’t the gaming commissions publish this information for all of the standard games?
Varies by state. Some are not required by law to disclose.
Full of ads but the info is all compiled here:
So does this mean I can find out, oh, I got three cherries! That was a one in 800 spin! These seem to be about general odds.
Modern slot machines are computer controlled. Casinos actually have the ability to change the odds fairly easily from a computer back in their offices somewhere, unlike the old spinning wheel machines where the odds were fixed and were based purely on the game’s mechanical bits. Modern machines still have spinning wheels, but that’s just a visual effect. The actual output which gets displayed on the spinning wheels is determined by a random number generator or some kind of pseudo-random algorithm in the computer hardware.
The computer code is very tightly regulated, and the ROM chips in the machine are actually tagged with tamper-proof labels. I’m not sure if that serves any useful purpose with modern electronically programmable ROM chips.
There are also limits on how much the casinos can change the odds. As was already mentioned, most states have minimum payouts that are required by law.
There’s a YouTube channel hosted by a former slot machine technician. He has a lot of videos about playing various games, but look carefully, and you’ll find a number of educational videos about how slots work, how their payoffs are determined and adjusted, scams, myths, and so on.
Here is the channel:
I used to work for Gaming Laboratories International, which, among other things, is an independent third party that certifies that slot machines satisfy gaming regulator requirements in various jurisdictions. I specifically worked in the math department verifying that the math models of slots and other casino games were compliant with regulations in jurisdictions all over the globe.
The answer to your question is going to vary from jurisdiction to jurisdiction. Every slot machine will have what is called a PAR sheet for each configuration of the game which will include extremely detailed probability information about the game (aside: PAR is a somewhat outdated acronym for Paytable and Reels). Here’s an article that has an example PAR sheet about 2/3 the way down (The PAR Sheet: A Look Under the Hood of a Slot Machine Game – Know Your Slots). The public availability of PAR sheets varies from jurisdiction to jurisdiction. You can also find leaked PAR sheets online for many games.
Additionally most slot machines will have help screens that a user can peruse without committing to playing the game. In some jurisdictions these help screens are required to give accurate probabilities for winning some or all of the advertised prizes.
If this question is an idle curiosity, this is about as far as it can be answered. If on the other hand, this is a real question about an actual event, we could probably go a lot farther but the OP would need to supply a lot more info about the specifics of the event.
The PAR sheets for many games are online. Here are some.
No, you can’t. You’d need to be able to see the PAR sheet for that machine, and the slot makers don’t make those public. A few have leaked out, and I have them on my website, as don_t ask linked to, but for the overwhelming majority of machines, slot players are flying blind.
Many posters here are conflating the payout/payback with the odds of a specific kind of hit. Those are two totally separate things. OP asked about odds of a specific hit, not payback.
Odds of hitting the top jackpot are generally way higher than the 1 in 500,000 you guessed. I have an article about that, but I’m sure if I tried to link it in my first post here I’d get banned as a spammer. Go to the link that don_t ask dropped, and look for the “Slot Returns” link in the list of articles at the bottom of the page.