Calculating Symbol Frequency

Hi,

after reading a lot about slot machine payout calculations there is still something that I just don't get:

All of the payout calculations on the Wizard of Odds Website seem work the same way:
- define the reel strips/symbol frequency,
- define the payout table,
- calculate combinations/probabilities
- calculate return percentage

I have seen slot machines (at least in europe) that enable the owner to change the payout percentage of the machine.

How would that work? Does the machine/game create new reels? How would you calculate the symbol frequency, based on your payout table?


Best regards,
rogga

Interview with a Slot Manager - 1999
https://www.americancasinoguide.com/slot-machines/interview-with-a-slot-manager.html

Quote: rogga

Hi,

after reading a lot about slot machine payout calculations there is still something that I just don't get:

All of the payout calculations on the Wizard of Odds Website seem work the same way:
- define the reel strips/symbol frequency,
- define the payout table,
- calculate combinations/probabilities
- calculate return percentage

I have seen slot machines (at least in europe) that enable the owner to change the payout percentage of the machine.

How would that work? Does the machine/game create new reels? How would you calculate the symbol frequency, based on your payout table?


Best regards,
rogga

The return is based on the frequencies.

Quote: rogga

How would that work? Does the machine/game create new reels? How would you calculate the symbol frequency, based on your payout table?

The returns are easily configurable in any slot machine that has a computer chip inside.

In a mechanical slot (with actual spinning reels), the weighting of the stops on the reels are adjustable.

In video slots the actual reel strips are adjustable. For example, increasing the return might be achieved by adding more wilds to the reel strips.

In both cases, the idea is to make the change invisible to the player.

Sometimes it is done by altering how much the feature pays, so although the hit rate might be the same the average payout for it can be changed.

I'm not sure what exactly changes when the payout rate is changed, but I would assume that, exactly like you said, the reel strips would just change. I have read a couple of your articles on how the payout rate can be calculated, but it always comes down to the same procedure (definition of payout table, definition of reel strips, then do the math). In this case I am interested in the math too, but the other way around.

Is there a way to first specify a payout table, then a payout rate (e.g. 90%) and then automatically generate the reels in a way so their setup results in a 90% payout probability? I could not find an article that explains the math for this scenario.

I'm sorry if my question is not clear enough to understand, english is not my first language.

thank you all for your help and also the very interesting interview (even though I am still sure I've seen a possibility to change the payout quote - but that was like 10 years ago and I might of course be wrong - but I still enjoyed reading it).

The 'display' reels are fixed. But the symbols that are displayed in a spin are determined by a random number generator (RNG) and multiple sets of VIRTUAL reels. The RNG picks a number which is an index into the virtual reel. This is then mapped to the actual or display reel. The machine can have multiple sets of virtual reels - one set that increases the chances of a free games feature; one that increases the chances of a Hold-and-Spin feature; one that increases the chances of wild symbols appearing. And so on.

All modern slots are programmed with multiple RTP (return to player) rates. The operator can adjust the payout from 86% to 88% or 90% etc. The display reels remain the same - but the virtual reels are different for different RTPs.

Here is a good explanation of virtual reels and their role in determining the odds of any particular symbol landing on the payline /watch?v=Ur53m9zQ5sY

Like everywhere else, in slots there is a certain set of rules that will allow not to squander all the money in the first hours or days :

You can't spend your last money relying only on luck, because if you do want to profit and only win, it's impossible. Only free cache is invested, so that the game runs relaxed;
There are certain limit amounts to control the situation , there is even a specific name for them, which you will learn about later;
The bets are chosen according to your personal bankroll;
Playing at demo tables is not considered as shameful and will help you learn how to play, so you should not neglect them, they will help you develop a personal strategy. You don't need any real money for that;
Blocking emotions is very important. Adhere only to strategies and your mind;
Not hoping for a steady income. It is only entertainment, which will either bring money or vice versa, but will definitely take care of a good time.

Quote: WebberAgenc23

Like everywhere else, in slots there is a certain set of rules that will allow not to squander all the money in the first hours or days :

That is a 100% wrong.

Quote: DRich

Quote: WebberAgenc23

Like everywhere else, in slots there is a certain set of rules that will allow not to squander all the money in the first hours or days :

That is a 100% wrong.
link to original post

Spam account.

Quote: rogga

Hi,
How would you calculate the symbol frequency, based on your payout table?
link to original post

For the simplest reel slots, you can write a formula for the RTP (return to player) percentage. Payouts of a 3-reel single-pay-line payout machine are easy. For every possible payout just multiply probability of the three symbols on the payline times the payout to get the partial RTP. Then sum them all to get the total RTP.

If you put this in a spreadsheet, you can adjust the frequencies and see the RTP change.

If you want to reverse engineer a slot, you can just run in demo mode online and collect statistics. Many slots have 128 stops, but I know of several that have only 24 stops.

1/24 = 4.17% It doesn't take long to see that all the stop frequencies in the data sample are close to multiples of 4.17%. Many symbols appeared exactly three times, but some high value symbols appeared only once or twice on several reels. I quickly had an exact model of the reels.

By stopping a video, you can easily watch the whole reel go by. This allows a quick reel mapping, but only works if the reels are static and do not change. In many games, the reels do change. Stacking games modify the reels every spin. They choose a symbol to stack and then they put many of those symbols on the reel for one spin. See Scarab as an example. Many games use different reels for bonus spins versus base spins.