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Fact or Fiction?


Twenty years after the introduction of the “virtual reel” slot machine, the myths about how slots operate continue

by Frank Legato

For most of the 20th century, the slot machine was pretty much the same. Three reels spun around, prompted first by springs loaded in a handle and later by electrical switches. Where those reels landed when stopped by a separate mechanism was largely a function of gravity.

Since the period of time the reels spun for and the number of symbols on each reel remained constant, odds and probabilities could be calculated by mapping the reel symbols, and wagering systems could be developed to give math-savvy players an advantage.

It all changed in 1984 when Inge Telnaus was issued a U.S. patent for a computerized method of determining the results of a slot machine. Ever since this system was implemented, players have mistrusted the machine. The result has been a remarkable set of myths about how this computer selects a winning result, and how a player can have the best chance of beating the odds and walking away a winner.

People dislike trusting anything to computer technology, including the notion that the result a computer generates is truly random. So the myths have persisted, ranging from logical but wrong to truly ridiculous. Now it’s time for Casino Player to publish its periodic rundown of the most popular notions about slot machines that are actually fiction, and to give you the real facts.

Slot Machines

But first, one should know what Telnaus actually invented with his computerized slot system, which is the basis on which all modern slot machines are designed. The system—the patent was soon purchased by then-young IGT, which held it until it expired in 2004—became commonly known as the “virtual reel” system, because with it, slot results were no longer dependent on the movement of the physical reels. Instead, each reel result was assigned a number in a computer program. The low-paying or nonpaying results were each assigned many numbers, the high jackpot symbols just a few or one. These numbers were all burned into a game chip, with a random number generator device (RNG) that would cycle through all the numbers constantly, at lightning speed. When the handle was pulled or the spin button pushed, the device would generate one number in the program at random.

By manipulating the sets of numbers assigned to each symbol or reel result in the program, manufacturers were able to calculate theoretical payback percentages based on a computer simulation of millions of spins. However, a math wizard could no longer calculate the odds by counting the symbols and looking at the paytable, because the physical reels were now meaningless. The RNG was selecting the outcome, and signaling a computerized stepper motor where to stop the physical reels. The reels themselves now functioned to display the result chosen at random by the RNG.

We write more about the RNG and the virtual reel system than about most other slot subjects, particularly in our letters-to-the-editor department. If the questions our readers send us month after month demonstrate anything, it is that many of the stubborn myths about how slots operate are still believed by many players.

To follow are some of the most popular myths, and the facts to disprove them. We have no doubt that the myths will persist after our readers peruse this article—they have, in fact, taken on a life of their own. But we will keep trying to provide you with the facts nonetheless.

Myth: The casino can flip a switch to make slots tighter if too many people are winning, or if the casino is crowded. When business is slow, they can change back to higher paybacks.

Reality: The old “payback switch” has been one of the most persistent myths out there, but the fact is this: There is no switch or button or mouse-click on a computer screen used by casino slot personnel to alter the payback programs of slot machines on the casino floor.

Here’s how it works. Slot manufacturers demonstrate their game software in prototypes to slot department officials of casinos. If those officials like what they see, they order a bank of the machines, choosing from typically six or seven available theoretical payback percentage programs offered by the slotmaker. Those payback percentage programs are burned into the game chip at the factory, by programmers who have determined the theoretical return by running computer simulations duplicating several years of game play. The chips have also been approved by regulatory agencies, which run the same simulations to verify the theoretical payback percentage. They are delivered to the casino, and the game chips are locked into the machine.

Once locked in, the chips generally remain in the machine for the life of that game. They can be replaced if the machine is not earning, but that also requires regulatory verification, and in practice, the casino will change out the entire game instead of the payback percentage if the game is not making money for the casino.

Under current regulations, changing payback percentages requires opening slot cabinets and switching out chips, with regulators informed ahead of time and present when the change is made to verify the new percentage. Casinos simply do not have that kind of manpower.

Percentages are a function of casino policy within any given denomination—if you doubt that, look at our annual loose slots awards in this issue. Those numbers are similar every year, and they reflect actual payback, not theoretical. If a game does not earn, casinos do not change the percentage. They change the game.

Myth: If a computer programmer can determine a game’s payback percentage, the results of any spin cannot be truly random.

Reality: The results of any given spin are random. The programmer’s manipulation of the payback percentage is achieved by manipulating the universe of numbers from which that random result is chosen. If more numbers are assigned to lower or nonpaying results, the payback percentage will be lower. Assign more numbers to jackpot results, and the payback percentage will be higher—not because of the manipulation itself, but because of the laws of probability once the universe of numbers is altered and one of those numbers is generated at random.

Imagine the computer programmer designing a slot game that displays the simple flip of a coin. He has assigned one number to heads, one number to tails. Heads will come up as often as tails over the long run, so the coin-flip game will return as much as it takes in—he has programmed a 100 percent payback percentage into the coin-flip game. But the actual flip of the coin is random. It may land on heads five times in a row, or it may land twice on tails followed by three times on heads… but in the long run, it will even out to a 100 percent payback percentage. The actual flip, however, just like the actual generation of a result by the RNG, is random.

Myth: The payback percentage is always better when wagering the maximum.

Reality: The computer does not care how much you wager. It is going to generate a number at random, regardless of how much you bet. The truth is, with a straight “multiplier” game—i.e., the jackpot amounts are exact multiples of the single coin amount: 10 coins for one wagered; 20 for two; 30 for three—there is no inherent advantage in betting the maximum. The payback percentage and hit frequencies are the same, regardless of the wager.

This reality is altered only by the pay schedule or by multiple paylines. If it’s a “buy-a-pay” schedule, you will see on the table that some jackpots are only activated with the second or third coin. In this case, the payback percentage does rise with the amount wagered. But it is not the wager itself that drives this rise; it is the pay schedule. The actual result will be the same regardless of the wager—only the payoff will differ.

In the case of a multiline reel or video slot, the payback percentage will be lower if all paylines are not activated, and will rise as each coin activates another payline. Once all paylines are activated, it is the same as a straight multiplier—if you bet at least enough to activate all the paylines, the percentages and hit frequencies are constant from that point.

Myth: The slot machine pays out more (or less) when I insert my slot club card.

Reality: Another persistent myth is the function of the slot club card. The card reader is not connected in any way to the slot computer’s game chip. In fact, it is in an entirely separate location, in the top box of the machine. The reader is there only to record your play: Coin-in and coin-out. It transmits that information to the central slot club computer for the sole purpose of rewarding you for loyal play. The slot club card has absolutely no effect on the results that will be achieved by the slot’s RNG program.

Myth: A casino employee familiar with the slot games can tell me accurately when those slots are “due” for a jackpot.
Reality: Players often tip slot personnel to direct them to a game that is “due” to hit, and when they do, they are wasting their money. Each spin on a slot machine is entirely independent of any other spin.

The slot machine’s RNG cycles through the entire set of numbers more than a hundred times every second. Therefore, even if a jackpot has not hit for weeks on any given machine, it does not mean it will hit today, tomorrow or next week. Or it could hit on the next spin. There is no way for you, or that slot attendant, to know for sure.

This is even true in the case of a progressive, although in the case of a progressive link that has been in one place a long time, and an employee who has witnessed the neighborhood in which it has hit consistently, a progressive being “due” could be a worthwhile tip. As we’ve seen in Megabucks, once a progressive reaches unprecedented proportions, “due” becomes a self-fulfilling prophecy because of the phenomenon of “jackpot fever.” More people will play, increasing the likelihood that it will hit sooner rather than later. But still, as we said, there are no guarantees—an unprecedented jackpot level on a progressive still does not mean it’s going to hit today, or tomorrow. Save your tip money for the cocktail server.

Myth: A player who sits down and hits a jackpot immediately when a player vacates his seat “stole” that player’s jackpot.

Reality: No one can “steal” your jackpot. As we noted above, the RNG program is cycling through the entire set of possible results many times each second. To believe the next player has “stolen” your jackpot is to assume that you would have hit the spin button at the precise nanosecond that he did. The odds of that happening are astronomical. You could have hit a jackpot, or you could have kept losing. There is no way to tell—so don’t worry about it.

Myth: Casinos always place the loosest machines on the ends of the row, so people can be seen winning.
Reality: There may be a grain of truth to this one—but not much. It is common sense to place high-paying machines in prominent locations, but in reality, slot managers mix them in throughout the floor. As we noted earlier, payback percentages are a matter of policy within any denomination, so the quarter game on the end is going to have nearly the same long-term payback percentage as the one in the middle. In the short term, it’s going to have the same cycles as any other game on the floor.

Myth: The result in second-screen bonus events is predetermined, so if there is a choice of hidden bonuses, it doesn’t matter which choice the player makes.

Reality: It does, in fact, matter which choice a player makes in the so-called pick-a-tile style of bonus game. When the bonus is initiated, the machine’s RNG selects an entire screen of bonus amounts. After that, it’s up to the player to pick the higher or lower amounts.

Many of the newer games in this style verify this point by revealing all possible choices after the player makes his selection. This feature offers nothing for the game; manufacturers began doing it this way because they, as us, received constant inquiries from players as to whether their choices in the bonus round really mattered.

Myth: By counting the number of spaces and symbols on the reels in relation to the award for each winning combination, someone skilled in mathematics can determine the odds on a reel-spinning game.

Reality: This was actually true in the old days, before the invention of the virtual reel system. However, as we noted in our introduction, the number of symbols on the reels now means nothing. The probability of any one symbol landing on the payline is now governed by the computer’s RNG. By assigning many numbers to a single symbol or set of symbols, the programmers are creating what is, in effect, a reel strip with hundreds of symbols, rather than the 22 stops on a physical reel. It is now a “virtual” reel. The reel strips on a traditional slot serve the same purpose as a video screen—to display the result chosen by the RNG. Counting the symbols and doing math achieves absolutely nothing, other than perhaps a headache.

Myth: Heating up the coins or cooling down the coins increases the chance of winning.
Reality: This one is still out there, and it’s as bizarre as it has ever been. People actually have heated coins with a cigarette lighter or packed them in ice before inserting them. The result? It made the coins hot or cold. It does nothing else. Whether you like ticket-printing slots or not, at least the new games will finally put this myth to rest.

Myth: If the reels wiggle, it means the machine is getting ready to pay out.

Reality: See above. The reels are only there to display the result achieved by the computer. Whether they wiggle, jump, dance a jig or sing the national anthem, the result will be the same—a display of the result corresponding to the RNG’s choice of a number in the program.

There are many other myths, which we address from time to time in our letters sections, and which persist despite logic and factual information… pulling the handle versus pushing the button, the casino will never let you win, slot attendants change percentages when they work on the machine…. We could go on and on. However we only have so much space for a single article, and we need to leave something for our letter files.

We will close with this one thought: Most myths are based on the notion that the casino is out to somehow illegally cheat the player out of his money. If you believe that, consider this: They don’t have to. They have a license to take your money with a 10 percent house edge on most of the games, and we players give that edge up willingly.

Fact or Fiction? Slot Machines.

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