desertair
desertair
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June 1st, 2016 at 9:35:44 AM permalink
In this article written by the Wizard, he explains the entire process for creating a slot machine and describes the probabilities and such. Very helpful.

http://wizardofodds.com/games/slots/atkins-diet/

Does anyone know why the reels have a length of 32?

I ask because I'm building a simple 3 reel slot machine as part of my learning the C# programming language. I have a simple RNG and assigned values to reel positions, but I am working on the challenging part where I have to make the game somewhat challenging. Understandably, if you make each reel have more "rows" then you can increase the number of combinations, but why 32 in the case of the Atkins Diet slot game?
rsactuary
rsactuary
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June 1st, 2016 at 9:52:46 AM permalink
for a video slot machine, reel length can be whatever you want it to be.

As an example of the extreme.... there's a slot machine out there called the Green Machine. You can probably YouTube some videos to see it in action.

But 3 "stops" show up on each real, and unlike most slot machines where you need to match 3 symbols on a payline, for this machine, whatever dollar amount shows up on the reel, is what you win.... and the reels are independent of each other. Top prize on each reel is $1000 on the $1 coin version of this machine.

So let's think about that for a minute.... If the casino wanted to offer 100% payback, and the $1000 symbol was the only symbol on the reel... the reel would have to be 3000 stops in length. Now consider that they want to make some money so let's say the payback is 90%. Then the reel has to be 3333 stops in length.

Now lets consider that there are other prizes and that the top prize probably doesn't return more than 5% of each dollar spent.... well then the reel length needs to be 3333/.05 = 66,660 stops long!!!!!!!

In some of the Wiz's analysis of other video slots, the reels within a game don't even need to be the same length.
desertair
desertair
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June 1st, 2016 at 9:55:49 AM permalink
Quote: rsactuary

for a video slot machine, reel length can be whatever you want it to be.

As an example of the extreme.... there's a slot machine out there called the Green Machine. You can probably YouTube some videos to see it in action.

But 3 "stops" show up on each real, and unlike most slot machines where you need to match 3 symbols on a payline, for this machine, whatever dollar amount shows up on the reel, is what you win.... and the reels are independent of each other. Top prize on each reel is $1000 on the $1 coin version of this machine.

So let's think about that for a minute.... If the casino wanted to offer 100% payback, and the $1000 symbol was the only symbol on the reel... the reel would have to be 3000 stops in length. Now consider that they want to make some money so let's say the payback is 90%. Then the reel has to be 3333 stops in length.

Now lets consider that there are other prizes and that the top prize probably doesn't return more than 5% of each dollar spent.... well then the reel length needs to be 3333/.05 = 66,660 stops long!!!!!!!



OK wow that is a crazy example. I'll check the vids of it on YouTube.

Thanks for the quick answer!
rsactuary
rsactuary
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June 1st, 2016 at 9:59:25 AM permalink
https://www.youtube.com/watch?v=bf33dTrTHsY

Here's an excellent example of it in action.
DiscreteMaths2
DiscreteMaths2
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June 1st, 2016 at 10:01:40 AM permalink
Check out this video on virtual reel mapping: https://www.youtube.com/watch?v=Ur53m9zQ5sY I believe in the Wizard's example he does 1 stop to 1 number and then the game relies on symbol distribution. With virtual reel mapping not only can you set weights for the symbols but you set weights for the stops, so your actual reel length is arbitrary.
Assume the worst, believe no one, and make your move only when you are certain that you are unbeatable or have, at worst, exceptionally good odds in your favor.
rsactuary
rsactuary
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June 1st, 2016 at 10:03:03 AM permalink
Typically the more you pay in, the higher the return for a slot machine.

Now this is pure conjecture, but for the Green Machine, it's entirely possible that the first reel is set up at 85%, the second reel at 87.5%, the third reel at 90%, fourth at 92.5% and fifth at 95% to mimic the better return for higher amount paid that slot machines tend to do.

No way to actually prove it without getting the PAR sheets, which typically aren't public.
rsactuary
rsactuary
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June 1st, 2016 at 10:06:18 AM permalink
Quote: DiscreteMaths2

Check out this video on virtual reel mapping: https://www.youtube.com/watch?v=Ur53m9zQ5sY I believe in the Wizard's example he does 1 stop to 1 number and then the game relies on symbol distribution. With virtual reel mapping not only can you set weights for the symbols but you set weights for the stops, so your actual reel length is arbitrary.



this is true for mechanical reel slot machines. Not so for electronic wheels, which the Wiz assures us each symbol gets an equal weight.
DiscreteMaths2
DiscreteMaths2
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June 1st, 2016 at 10:19:13 AM permalink
Quote: rsactuary

this is true for mechanical reel slot machines. Not so for electronic wheels, which the Wiz assures us each symbol gets an equal weight.



Is that the law in Nevada ? For New Jersey I could find no such law you are just limited to "Slot machines shall not offer a play with odds greater than 100 million to 1" , " shall not permit a symbol above or below the top jackpot symbol to be mapped more than six times more frequently than any other symbol on a reel strip." and then just some more rules for bonus games, RTP, etc.
Assume the worst, believe no one, and make your move only when you are certain that you are unbeatable or have, at worst, exceptionally good odds in your favor.
desertair
desertair
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June 1st, 2016 at 10:23:50 AM permalink
Quote: DiscreteMaths2

Check out this video on virtual reel mapping: https://www.youtube.com/watch?v=Ur53m9zQ5sY I believe in the Wizard's example he does 1 stop to 1 number and then the game relies on symbol distribution. With virtual reel mapping not only can you set weights for the symbols but you set weights for the stops, so your actual reel length is arbitrary.



That is a very helpful video. I had a hunch it was built like that when I was looking at this research paper during my early stages of planning the program:

http://jgi.camh.net/doi/pdf/10.4309/jgi.2009.23.5

Page 93 shows how the RNG has a range of 1-72 while the reel itself is 1-22.

On my program, I initially designed the reels to have 6 rows, with symbols of A, B, C, 7, Cherry, and BAR. (note that I didn't think to include spaces but will now).

Winning combinations include matching 3 symbols or the single occurrence of a cherry.

Let's just say that my initial testing makes you win way too frequently. Since each reel has 6 possible stops, and a cherry is on each reel, you can win quite easily.

I now need to expand the size of my virtual reels and make the cherry less frequently hit by the RNG.
ThatDonGuy
ThatDonGuy 
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June 1st, 2016 at 10:26:50 AM permalink
Quote: desertair

In this article written by the Wizard, he explains the entire process for creating a slot machine and describes the probabilities and such. Very helpful.

http://wizardofodds.com/games/slots/atkins-diet/

Does anyone know why the reels have a length of 32?


The "obvious" answer is, a power of 2 is used as most RNGs generate a number in the range of a power of 2 (if there are 5 reels, a number from 0 to 230-1 is generated; this is five 6-bit (i.e. 0 to 31) numbers, one for each reel). 32 might be chosen because it is the smallest power of 2 greater than 20, which I am led to believe is the "traditional" number of symbols on a "old style" slot machine; it could also be because, as there are 5 reels, 32 symbols per reel require 30-bit numbers, but 64 symbols would require 35-bit ones, which are larger than a 32-bit integer.

(Speaking of which, I was a little surprised to see "modern" slots for sale at a pinball show I went to near Sacramento recently, but then again, I definitely remember seeing video slots in Reno in 1985, and California has a "if it's at least 25 years old, it's an antique and you can sell it" law.)

Quote: rsactuary

this is true for mechanical reel slot machines. Not so for electronic wheels, which the Wiz assures us each symbol gets an equal weight.


I thought it was that multi-line slots had reels where each symbol had an equal weight (otherwise different lines would have different EVs), whether electronic or mechanical. Then again, do any one-line-only electronic (i.e. video) slots even exist, other than computer/online emulators of existing mechanical machines?

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