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# More on Randomness and the RNG

12 September 2005

John,

I still have a hard time with the RNG as you explain it.

Random means having no specific pattern. That each number in a set has an equal chance of being chosen. Then why is it that slot machines in general will eat for days or weeks and then pay out numerous high-paying combinations 2 or 3 times in a day for sometimes 2 or 3 days in a row?

Being a casino frequent visitor (sorry to say), I have seen this happen many, many times. Therefore, in my opinion, the best chance you have at winning is to play a slot that has paid out a winner earlier that same day. If you go to the same casino often you can see which machines are eating and which are paying. I have done very well following this method. It's not perfect and I don't mean you will win every time but your winning odds are definetly better. It seems after a particular machine eats enough money, it then generates more winning combinations for a length of time.

Does money intake amount have any effect on the RNG chip? If not, why would I see this pattern as I just described?

Thanks,
Jim

Dear Jim,

Your definition of random is fine for English majors, but not precise enough for mathematical purposes.

Consider three tosses of a fair die. Should we be concerned if we happen to toss 1-2-3? Or 1-1-1? Would you feel better if we tossed 4-3-6?

How about 2-1-2? That pattern is significant to me because it is the area code for Manhattan. It might mean nothing to someone from San Francisco, who sees significance in 4-1-5.

In reality, the probability is the same for each of these outcomes and the fact that they occurred should not cause us concern. If they appeared more frequently than 1 out of 216 tosses, then we can start to be concerned.

I have to ask you this question: Did you watch the slots in question, those that ate coins for days or weeks at a time and then paid off, for 24 hours each day?

No? Then how do you know what happened while you weren't watching them? How do you know that the coin-eaters weren't coin-payers when you weren't there? And maybe those machines that paid out numerous high-paying combinations for days in a row were cold when you weren't there.

It's like not seeing all of the movie Titanic. If you saw only the first part, you'd think it was an adventure movie. Just the middle, you'd think it was a romance. And just the end, a disaster flick. You have to see the whole thing to get the full picture.

You didn't see the machines long enough to know what was really going on with them.

To answer your last two questions, the RNG function is not influenced by how much money has been played or paid out. You saw the patters you did because 1) you had a limited period of observation, and 2) the presence of patterns does not in and of itself make us question randomness.

Best of luck in and out of the casinos,
John

John,

You know and I know there are people out there in the casinos losing their money every day. And you are to many of us a man who could provide an answer for better results on slots.

I'm refering to modern video slots and the RNG. In Europe, where I come from, most popular are not the IGT machines, but Novomatic machines. These are also much more predictable than IGTs. So people prefer to play these.

Now, to my quetions.

All Novomatic machines are very much bonus oriented. In other words - if you don't hit the bonus round, you are most likely busted.

One of the most played machines is Dolphin's Pearl. It's the toughest one. Usually you must spend 100 Euro, 200 or even more to hit the bonus round. You have to get three pearls and you get 15 free spins at 3x pay. So they don't come for, say, 1000 or more spins. But guess what - when you hit a bonus round, you are very unlucky if you dont get it RETRIGGERED (again three pearls) at least twice! Once I even got 195 free games!

Does it make any sense? I read once in your answers that free spins are just like normal spins. My answer would be - the machine is ready to give out a certain amount and retriggers the free spins until the goal is reached.

The other popular machine is Sharky. I played it so much, I know every move it does. I certainly know, when it's due to hit the bonus round, bur the symbol that ought to come misteriosly dissapears (the reel changes symbols in the last moment). It brings mind to an article about the RNG's being supervised by another chip (that probably balances payout percentage), which can alter the RNG result.

I really want to know your thoughts, because I believe RNG is much like a car. I can run by itself, but you are stil steering it. Life would be so much easier if we players could know the real secrets of video slots.

Ales, Slovenia, EUROPE.

Dear Ales,

We have to be careful here and take into account differences between machines and between regulations in different countries.

On the American-made machines I've seen, when you win free spins, the probabilities of hitting winning combinations on the free spins are the same as on normal game play, unless the reel symbols are changed, as during a bonus round.

Now let's bring in different requlations. I know in England, at least, machines do have a governor function that keeps the money paid out by a machine in a relatively narrow range around the machine's theoretical payback percentage. I don't know how the function works other than knowing that it will affect the results of spins on the machine.

This sort of thing is absolutely illegal in the U.S. Results on machines must be determined at random.

I suppose you could watch a machine and play it only when it has had a cold spell, in the theory that the payback-governor would have to kick in and make the machine pay out. But, like Jim in the question above, you really have to watch the machine 24x7 to have a true picture of what's going on with it.

Best of luck in and out of the casinos,
John

Send your slot and video poker questions to John Robison, Slot Expert, at slotexpert@comcast.net. Because of the volume of mail I receive, I regret that I can't send a reply to every question. Also be advised that it may take several months for your question to appear in my column.

John Robison

John Robison is an expert on slot machines and how to play them. John is a slot and video poker columnist and has written for many of gaming’s leading publications. He holds a master's degree in computer science from the prestigious Stevens Institute of Technology.

You may hear John give his slot and video poker tips live on The Good Times Show, hosted by Rudi Schiffer and Mike Schiffer, which is broadcast from Memphis on KXIQ 1180AM Friday afternoon from from 2PM to 5PM Central Time. John is on the show from 4:30 to 5. You can listen to archives of the show on the web anytime.

#### Books by John Robison:

The Slot Expert's Guide to Playing Slots
John Robison
John Robison is an expert on slot machines and how to play them. John is a slot and video poker columnist and has written for many of gaming’s leading publications. He holds a master's degree in computer science from the prestigious Stevens Institute of Technology.

You may hear John give his slot and video poker tips live on The Good Times Show, hosted by Rudi Schiffer and Mike Schiffer, which is broadcast from Memphis on KXIQ 1180AM Friday afternoon from from 2PM to 5PM Central Time. John is on the show from 4:30 to 5. You can listen to archives of the show on the web anytime.

#### Books by John Robison:

The Slot Expert's Guide to Playing Slots