Darmafi Joined: Dec 18, 2022
• Posts: 7
March 11th, 2023 at 6:24:41 PM permalink
Ive spent some time gathering a log of around 2000 spins for a 3 reel slot with 8 pay symbols, 3 wheel-stops per symbol/24 stops per wheel. I’ve calculated a roughly .84% rtp excluding the 2 progressive Jackpots. Is there a pre made excel spread sheet or something where I can plug in all my data to figure out if I have something worth playing here?
ThatDonGuy Joined: Jun 22, 2011
• Posts: 5947
Thanks for this post from: March 11th, 2023 at 8:43:52 PM permalink
I don't think so, as you would need to list every paying combination and how likely it is.

There should be a way of calculating it "from scratch," however. If every stop is equally likely (something not necessary true on a single-line slot), and every stop has a pay symbol (i.e. no blanks), then there are 24^3, or 13,824, different possible results, but since every pay symbol is equally only, only 8^3 = 512 results need to be considered. Add up the values of each possible result, assigning the variable "p" to the large progressive and "q" to the small progessive, and you should be able to generate an equation where (number of large progressive results) * p + (number of small progressive results) * q + (the sum of (number of times a particular non-jackpot result happens * what that result pays)) = 512 * what you paid to play; that is the break-even point. Note that the break-even point is in terms of both p and q.
Darmafi Joined: Dec 18, 2022
• Posts: 7
March 11th, 2023 at 9:33:33 PM permalink
First of all, thank you for the info!

If I’m confident enough in my RTP estimate of .84 could I potentially just use my data set to determine a rough probability for “p” and “q” and then work out the EV using those variables plus the rtp/betsize?

To figure out -just- the JP probability using my data would it be correct to first find the probability of landing the correct symbol in -each- reel then taking those three results (p1,p2,p3)^3?
DogHand Joined: Sep 24, 2011
• Posts: 1314
March 11th, 2023 at 10:58:45 PM permalink
Quote: Darmafi

First of all, thank you for the info!

If I’m confident enough in my RTP estimate of .84 could I potentially just use my data set to determine a rough probability for “p” and “q” and then work out the EV using those variables plus the rtp/betsize?

To figure out -just- the JP probability using my data would it be correct to first find the probability of landing the correct symbol in -each- reel then taking those three results (p1,p2,p3)^3?

Darmafi,

If we know, for example, that the number of jackpot symbols is 3 on reel 1, 4 on reel 2, and 1 on reel 3, then (assuming 24 stops per reel and equal probabilities for each reel stop as per your original post) we get

p1 = 3/24, p2 = 4/24, and p3 = 1/24

and so the jackpot probability is simply their product:

p = p1*p2*p3 = (3/24)*(4/24)*(1/24) = 12/13,824 = 1/1,152 = 0.0008681...

so 1 chance in 1,152 of hitting that jackpot.

Hope this helps!

Dog Hand
Darmafi Joined: Dec 18, 2022
• Posts: 7
March 12th, 2023 at 5:25:17 AM permalink
It is definitely helpful, and much appreciated. I’m really hoping you can tell me if my math/logic is way off the rails here or not.

The following represents the frequency for which the two jackpot symbols (A) and (B) were observed in the correct winning position within their respective reel. (There is only 1 possible winning configuration for each of the two jackpots.)

[2000 total spins]

For Jackpot A:

Reel #1 55
Reel #2 88
Reel #3 84
Combined probability: .00005

For Jackpot B:

Reel #1 106
Reel #2 106
Reel #3 55
Combined probability: .00008

So I’m wondering if the following formula/process would help solve for when a wager on this slot becomes break even or +ev

(I apologize in advance for my horrible attempt at math notation, I realize it’s brutal, really hoping you can piece it together without getting sick)

(n) = Betsize
(a) = Jackpot A’s current value
(C) = jackpot A’s combined probability
(b) = Jackpot B’s value
(P) = Jackpot B’s combined probability
(R) = base RTP

((nR) - n) + ((aC) + (bP)) = ev? :/
ThatDonGuy Joined: Jun 22, 2011
• Posts: 5947
March 12th, 2023 at 7:53:32 AM permalink
Quote: Darmafi

First of all, thank you for the info!

If I’m confident enough in my RTP estimate of .84 could I potentially just use my data set to determine a rough probability for “p” and “q” and then work out the EV using those variables plus the rtp/betsize?

To figure out -just- the JP probability using my data would it be correct to first find the probability of landing the correct symbol in -each- reel then taking those three results (p1,p2,p3)^3?