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# Does the programmed payout percentage override the RNG?

28 August 2006

I understand the RNG ... But if slots are pre-programmed to pay out 90% (or some other percentage), doesn't the programmed percentage override the RNG and signal to start paying out when the payout percentage is not getting near the programmed amount?

Mere random chance could keep that machine paying out 30% or some other low percentage for a long time.

Jack

Dear Jack,

The first problem with your argument is that you're looking at segment of the machine's performance and not the total picture. Once a machine has gotten a sufficient amount of play, individual events have very little effect on a machine's actual payback. So even if a 90% long-term payback machine paid back only 30% for "a long time" — however long that is — the machine's actual payback could still very well be within the range expected for the number spins played on it.

The second problem is that your scenario is not likely to happen. Numbers from the RNG are used to select combinations at random from a pool of combinations. The combinations are assigned various payoff amounts such that the pools pays back a certain percentage. Over time, the actual payback of a machine will tend to approach the payback of the pool, the long-term payback. While it's possible that a machine's actual payback can be far away from its long-term payback, that situation gets less and less likely the more play a machine gets.

The final problem is that machines must display the result determined by the RNG. Any "secondary decisions" that alter that result are illegal.

Best of luck in and out of the casinos,
John

John,

Just read your latest response to the question about "80-year-old lady won 10 million dollars on a 5-cent video poker machine in Atlantic City".

First of all, it was a 5-cent machine, but she no doubt played MAX BET (either \$2 or \$3) to win the \$10 million. Much more importantly, it was a nickel MEGABUCKS machine, not a video poker machine.

Joe

Dear Joe,

Thanks for the correction. It looks like my correspondent who saw the lady win was mistaken about the type of machine.

Best of luck in and out of the casinos,
John

Good afternoon, John,

The following came in with a question in your July 17 e-mail column.

The paper the other day said that an 80-year-old lady won 10 million dollars on a 5-cent video poker machine in Atlantic City.

Since I don't frequent Atlantic City, I can't say for sure, but this certainly seems like an improbable payoff even for a linked group of machines. I have never seen anything even close to this in Las Vegas. Do you think it was correct or perhaps a typo?

I do have one real question about multi-line slots. We are always advised to play all lines. I understand that this effects hit frequency. My question is: Do the later lines have higher pay tables? In other words, would the payout (on a 9-line machine) with 9 coins bet on one line ultimately be the same as 1 coin bet on each of 9 separate lines? I am ignoring any progressive jackpots as they normally require maximum coins on all lines.

Clarence

Dear Clarence,

Thanks for the kind words about my column.

As Joe pointed out in the letter before yours, it was a Megabucks machine, not a video poker machine. The writer of the original letter made a mistake.

As for whether later lines have better pay tables, you can check any machine for yourself by looking at the pay table screens on the slot. Many, if not most, video slots are straight multipliers. Each payline has the same pay table and each additional coin played on a line merely multiplies the payoffs on the line without adding any bonuses.

Progressives, as you point out, are different. The last line with max coins played has a higher payback than the other lines because of the progressive jackpot.

The long-term payback playing 1 coin on each of 9 lines is the same as playing 9 coins on 1 line. The volatility will be different. Playing more lines spreads out your risk and gives you a smoother ride. You won't win big on any spin, but you also won't lose everything very often.

Letting everything ride on one line, on the other hand, will give you bigger winnings when you hit something, but you'll also have many more spins on which you'll lose your entire bet.

If you like thrills and chills, you can bet big on one line. Or, if you're like me and prefer a little less excitement in terms of bankroll swings, you can spread your bet out over multiple lines. The choice is yours.

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