Stay informed with the
NEW Casino City Times newsletter!
Best of John Robison
The "Truth" About Slot Machines14 July 2008
You are correct that the RNGs in slot machines are more properly called Pseudo-Random Number Generators because the algorithms use deterministic functions. This fact is well documented. It would be cumbersome for slot writers to point out the the RNGs are really P-RNGs in every article, so we just call them RNGs and make the point that they're not truly random only when relevant to the article. In any case, labs test the stream of numbers produced by the P-RNGs and the stream passes many of the tests for randomness. The P-RNGs are good enough for the purpose of determining outcomes on a slot machine.
According to Casino Operations Management, the P-RNG used by IGT has a cycle of 4.3 billion numbers. The clock speed of the CPU is really irrelevant. Slots are not required to poll the RNG so many times per second. Slots poll the P-RNG only a few hundred or thousand times a second. The speed changes to make RNG cheating more difficult. The P-RNG will also be reseeded at various times, also to thwart RNG cheats.
There's another factor you have to keep in mind. The P-RNG isn't polled until the player initiates a game. The human factor adds another dimension. If you looked at the stream of numbers actually used to generate outcomes, the randomness of when a player hits the spin button combined with the P-RNG may produce a stream of numbers that are truly random.
Let's say that the P-RNG does cycle at least once a day. Why don't we see a jackpot every day? Because not every iteration of the P-RNG is used to generate an outcome. Nearly all of the iterations are ignored.
You wrote, "Winning spin and all other spins have absolutely equal probability to appear on the slot machine." Complete and utter BS. Do you hit three Double Diamonds as frequenly as you hit three mixed bars on a Double Diamond machine?
Machines have different hit frequencies. Do you hit as frequently on a Blazing 7s as on a Wild Cherry? Combinations, winning or losing, have different probabilities of landing on the payline.
It is true however that each virtual stop has an equal probability of being chosen.
"If you can guarantee percentage that simply means you are controlling either 'randomness' or 'probability' or both." More nonsense. Throw a die. Many times. I can guarantee you that the percentage of times you threw a 1 is very close to 16.67%. "If you guarantee something you cannot rely on probability and randomness." On the contrary, I can guarantee something because I relied on probability and randomness.
"Slot machines work with at least two or more predetermined tables of 'random numbers'." Congratulations! Hat trick. More nonsense. There's only one P-RNG algorithm in a slot machine.
I suggest you search for articles on Random Selection with Replacement. The principles behind this method of random sampling explain why a machine's actual payback will be very close to that calculated from the layout of the symbols on its virtual reels in the long run. The program doesn't need two tables of numbers, pay cycles and take cycles or anything else. Randomness alone is enough to ensure that a machine's actual payback will approach its calculated payback.
"That is the truth of the slot machines." I can point you to numerous books, web pages and statutes that confirm my description of how slot machines operate. Where's your evidence?
Best of luck in and out of the casinos,
Send your slot and video poker questions to John Robison, Slot Expert, at email@example.com. Because of the volume of mail I receive, I regret that I can't reply to every question.
This article is provided by the Frank Scoblete Network. Melissa A. Kaplan is the network's managing editor. If you would like to use this article on your website, please contact Casino City Press, the exclusive web syndication outlet for the Frank Scoblete Network. To contact Frank, please e-mail him at firstname.lastname@example.org.
Best of John Robison