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28 June 2004

If each spin on a slot machine is determined randomly by the RNG, how can casinos advertise a specific 98% payback?

Thanks.

Machines can have specific paybacks because the outcomes are drawn from a known population of outcomes. If we add up all the money returned by all the outcomes in the population and divide by the number of possible outcomes, we get the payback of the machine.

Here's an example of what this gibberish all means.

Suppose you have bag of 100 ping pong balls. Half the balls are red, 25 are white, and 25 are blue. You're going to draw a ball at random from the bag, record the color of the ball, and return it to the bag. Then you're going to repeat the procedure many, many times. (By the way, man created cable TV so this game wouldn't seem like a good way to spend an evening.)

When we look at your results after a few hundred or so drawings, we'll see that about half the time you drew a red ball, and about a quarter of the time you a white or a blue ball. As long as each ball is equally likely to be drawn, we can be sure that the distribution of colors in your results will be very to the distribution of colors in the population (the balls in the bag). Yet, you drew the balls at random.

What is random is which color of ball will be drawn next. On any given drawing, you had a 50% chance of drawing a red ball, a 25% chance of drawing a white ball, and a 25% change of drawing a blue ball. What is not random is what the distribution of colors will be in your results.

A slot machine works the same way. It draws an outcome at random from its population of outcomes. If there are 64,000 possible combinations and 8 of those are jackpot combinations, we know that the jackpot will land on the average 8 times out of 64,000 spins. The same holds true for all the other combinations. Over time, they will appear with the frequency predicted by the number of times they appear in the population of outcomes. Because we know how often each combination will appear, we can calculate the payback of the machine.

As with the ping pong ball drawing game, the only thing that is random is what the next outcome will be.

Best of luck in and out of the casinos,
John

Dear John,

I am planning to go to Vegas for my first time. I am from Toronto Canada. I have been frequenting our racetrack slots here as we have very many now and I just love the thrill and the noise!! It`s so exhilarating. I have won a few jackpots also (which is another reason I keep going back).

As these casinos are only slots, I don`t have any experience in other games that Vegas will be offering. Could you please give me a heads up as to where I should stay? The best casinos to play slots in as I am a first timer (I want to have a great experience). I expect to stay about 4 or 5 days and have a budget of 500 a day. What casinos comp the best for first timers and where is the best place in these casinos to find those loose machines? Any info would be a great help!!

Thanks, John.

Mike

Dear Mike,

Ah, a first trip to Las Vegas. I remember my first trip and all of the mistakes I made. Who'd have thought that a \$3.99 buffet would actually have edible food?

For your first trip, you probably should stay at a strip casino. The Mirage is very nice (note: I haven't stayed these since MGM bought it). Caesars Palace is also good and has better games than Mirage. Treasure Island is also a good choice.

Your best bets for finding club sign-up bonuses are asking at the club booth and checking in the local papers.

As for finding loose machines, most slot directors today order the same payback percentage for all of their games in a particular denomination, so all of their machines are loose (or tight, if you will).

Best of luck in and out of the casinos,
John

Hi, John,

I would like to win a good amount on nickel, quarter, and 50-cent slot machines, but I only can take just about 300 to 500 dollars to Atlantic City. What is the best way of winning more on what you have brought with you? I just don't like to lose the money that I brought with me to play. Please give me best advice for me to win.

Sincerely,
Lulu

Dear Lulu,

You really gave me warm, fuzzies when you asked where you could buy my book. You can get it online at Amazon, direct from Huntington Press (800-244-2224), and any bookstore can order it for you.

I don't know how long you're planning to spend in Atlantic City. Given that most people spend only a day or two in town, your bankroll is nothing to be ashamed of.

Here are my best pieces of advice:

• Stretch your bankroll by betting the appropriate number of coins the types of machines you play. Search on this site for my series on The Best Number of Coins to Play. This information is also in my book. The more spins you get from your bankroll, the more chances you have to hit a nice jackpot.
• Play machines that suit your personality and goals. If you want a life-changing jackpot, play the big progressives. If you want bonus rounds, play the video slots. If you want machines that hit frequently, albeit for smallish amounts, avoid low hit frequency machines. (See my series on Identifying Low Hit Frequency Machines on this site or in my book.)
• Join the slot club and use your card when you play. Take advantage of any comps you earn from your play, but don't play just to get a comp.
• Most importantly, have fun.

Nobody likes losing the money they brought to play, but it happens to all of us. Just make sure that your bankroll is discretionary money that is earmarked for entertainment and not money that should really spent on rent, food, or clothing.

Best of luck in and out of the casinos,
John

I have been playing 50-cent slot machines. When using a casino club card inserted in the slot, are your chances of hitting a winning combination any greater?

I always pay the max bet. Is that throwing it away faster or would I be better off playing one coin, two coin, three coin, etc.?

Thanks,
Ginger

Dear Ginger,

Some people claim that slots get tighter when you use your card because the casino has to pay for all the free goodies it's going to give to you. Others argue that machines get looser when you use your card because you're a regular customer and the casino wants to keep you coming back. Both can't be right. But they can both be wrong.

The truth is that using a card has no effect whatsoever on the outcomes on a slot machine.

Playing full coin is probably costing you money in the long run, but it depends on the types of machines you play. Almost certainly, playing full coin is eating up your bankroll faster than altering your bet.

I don't like playing a sequence of bets (e.g., one coin, two coins, three coins, three coins, two coins, one coin) because it makes no mathematical sense.

I prefer to play either one coin, full coin, or some number in between based on the type of machine I'm playing. You can find all the details in my series The Best Number of Coins to Play on this site. I'll summarize my advice here: One coin per spin on Multipliers, full coin on Buy-a-Pays, full coin on all progressives, full coin on Multi-Line, one coin per line on video slots.

Best of luck in and out of the casinos,
John

I just had to write to you to tell you what happened to me this past Tuesday.

We went to Boomtown Casino in Bossier City, Lousiana on Monday. I was playing quarter video poker. I had played about 5 hours and gave up and left this machine.

Then Tuesday morning I was playing the same machine and hit 4 Aces. I was excited and went to tell my husband. He had been playing different dollar machines. His cousin was sitting at a dollar machine next to him and my husband dropped a dollar in it and told him to play it. He won five dollars and kept playing. He got it up to \$265 and started losing. He was playing \$1 at a time. When he got to \$200 he decided to get off the machine. My husband told me I should come over there and play the Triple Diamond, since his cousin was getting off of it. I did, and I was playing \$1 at a time. After about 5 minutes, I was down to 5 credits. I went to a machine just to get more dollar tokens because my machine wouldn't take bills. When I dropped my dollar token in I accidentally hit MAX play (\$2). All of a sudden it came up 3 Triple Diamonds. Boy, was I surprised. I just won \$2,500. I told my husband's cousin that it probably wouldn't have come up if I had only played \$1. What do you think?

A few month's ago, my husband hit a jackpot with only \$1 and the guy that brought him his money said it probably would not have been the same if he had played more money.

Nan

Dear Nan,

The RNG switches outcomes hundreds of times per second. The outcome was three Triple Diamonds only for a small fraction of a second, which happened to have been exactly when you hit the Max Bet button. The RNG would have switched outcomes one hundred or more times in the extra time it would have taken you to press the Bet 1 and Spin buttons. You probably would have had a different result.

Why do I say probably? Consider a machine that has two jackpot symbols on each reel. Each of those symbols has to appear at least once in the virtual reels. There are at least eight ways to hit the jackpot on the machine. It's possible that the RNG would have chosen the same or another jackpot combination when you bet only one coin, but it's not likely.

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 two or more 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