Modern Slot Machine

Most modern slot machines are designed to look and feel like the old mechanical models, but they work on a completely different principle. The outcome of each pull is actually controlled by a central computer inside the machine, not by the motion of the reels. The computer uses step motors to turn each reel and stop it at the predetermined point. Dec 14, 2020 Many people enjoy slot machines for their ease of use and exciting possibilities. If you love playing slot machines and want to get serious about winning, you need to find a loose slot machine. A loose slot machine is a machine that has a higher than average payout. With a little cleverness and planning you can be winning large amounts in no time!

  1. How To Win At Slot Machines
  2. How To Beat A Modern Slot Machine
  3. Modern Slot Machine Repair
  4. Modern Slot Machines For Sale

Introduction to Understanding Advantage Play Slots

As a slot machine enthusiast, have you heard intriguing rumors of the secret world of advantage players? Perhaps you saw the “Susan B. Anthony” used to reward a poorly treated casino reviewer at the end of the third Ocean’s movie? Here, I separate fact from fantasy. Let’s start understanding advantage play slots.

This article has the following sections:

  • Introduction to Understanding Advantage Play Slots
  • What’s an Advantage Play, Anyway?
  • Understanding Advantage Play Slots #1: Game Themes
  • Understanding Advantage Play Slots #2: Team Approach
  • Understanding Advantage Play Slots #3: Modern Casinos
  • Sooner or Later, Advantage Plays Stop Working
  • Summary of Understanding Advantage Play Slots

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What’s an Advantage Play, Anyway?

In the gaming industry, an advantage play occurs whenever a gambler improves their odds of winning using gameplay knowledge not ordinarily available.

How To Win At Slot Machines

To help understand the general principle, consider a common non-gaming example: Credit card programs. Credit card companies exist offering cash-back for purchases. Chase Sapphire and Capital One Silver come to mind. Perhaps you’ve seen the television commercials with Samuel L. Jackson?

A credit card advantage play of such programs is to figure out how to make many, and I mean a lot of purchases to maximize cash-back. For example, perhaps you pay your rent or mortgage with that credit card.

Instead of paying directly with a credit card, which typically isn’t possible, you could find a reputable company that pays your rent or mortgage by check while you pay for the service via credit card. If the cash-back exceeds the small fee for the exchange, it’s an advantage play.

Or maybe you’re an entrepreneur with an Amazon fulfillment business. Perhaps you buy several items, put them together as a nice kit, then sell the package on Amazon. Why wouldn’t you purchase those single items with a cash-back credit card? If you sell at high-volume, you could push $10,000, or a whole lot more, through that credit card each month.

An advantage play example from the gaming industry, for table games, is card counting. This form of advantage play has a long and rich history. There’s even a major motion movie about blackjack card counting from 2008, 21.

But we’re interested in advantage plays involving slot machine casino gambling. In the next sections, we’ll work toward understanding advantage play slots, including my own relatively unique perspective for the modern casino environment.

Understanding Advantage Play Slots #1: Game Themes

The most popular slots advantage plays discussed online are about specific slot machine game themes. Every game theme has gameplay rules, which might have loopholes of which players can take advantage.

The essential approach to game theme advantage plays usually occurs during gameplay, although not always, which I’ll discuss in a moment. Class II competition-style slot machine game themes typically include a decision point for the player where there is a right or wrong answer.

Advantage players figure out in advance which answer is correct, sometimes only after extensive effort and research.

The difficulty with this approach is the assumption that it’s also an advantage play which applies to Class III Vegas-style games of chance at non-tribal casinos as well as Class II skill-based games typically only available at tribal casinos.

Do gameplay advantage plays exist for Class III slot machines? Once, they did. It was even somewhat prevalent, even as recently as 30 years ago. But, today? Not really.

What is my justification for this position? It’s based on thorough gaming regulations, including state-by-state testing of all game themes by independent laboratories. Very, very few game theme loopholes make it through such rigorous testing. See Advantage Play Against Slots (AP Heat Advantage Play) by Eliot Jacobson, Ph.D., published on March 6, 2017.

But I didn’t state that Class III slot machine advantage plays don’t exist. I said, they don’t really exist. What did I mean by this?

What I meant by this are the several circumstances where advantage plays can exist, if you want to expend the effort to find them. Just keep in mind that any serious advantage player carefully balances energy and cost with potential profit.

Put another way, figuring it out must be worth it. Some enterprising online individuals claim to have figured out a few game theme loopholes and share them freely. See Analyzing 4 Different Slots Advantage Play Methods by Randy Ray, published on May 11, 2019.

A few, usually new, audience members will ask my opinion for the best slot machines to play. My serious reply is those machines on which you win. Most of my audience agrees. In my opinion, looking for mistakes in game themes that made it past gaming regulators is a waste of time given how rare this occurrence has become.

However, lots of slots players think what casinos want them to think: Play your favorite slot machine game theme because, since it’s your favorite, you’ll win. Such an attitude from your casino isn’t gambling advice. It’s only marketing.

We’ve discussed game theme decision points and game theme loopholes, but there’s more. Another advantage play is to find slot machines with specific game themes played somewhat. A previous player could have paid for getting a slot machine closer to paying out.

A typical example is progressive slot machines with a must-win-by maximum jackpot. This amount is typically unknown. But extensive observation by an advantage player (AP) could allow them to figure it out, so they then only play progressives close to this limit.

The advantage play approach to progressive slot machines requires a great deal of patience to accomplish. If you’re interested in learning more about this approach, see my articles on progressive slots winning strategies:


Understanding Advantage Play Slots #2: Team Approach

Serious advantage players are typically part of closed communities. When an AP figures out how to take advantage of a slot machine, whether progressive, Class II, or otherwise, they are quite naturally secretive about it.

As I’ll discuss in a later section, many advantage plays are somewhat fragile. They are undoubtedly expensive in either time or money, sometimes both, to figure out. Therefore, APs will protect them like an investment.

But APs sometimes can’t figure out an advantage play without a team. Or they figure out an advantage play, as with a bank of networked progressive machines close to its jackpot limit, where every seat should have a team member sitting in it for the best chance of a return on investment.

Advantage players have figured out the cheapest way to learn a new advantage play is to watch known advantage players, then do what they do. These APs swoop in at the last moment to try to profit, such as taking one of those seats at an about-to-win bank of progressive slot machines.

Finally, it’s human nature to brag about our accomplishments. APs can and do make this mistake, but perhaps less often as they gain more experience at advantage plays. However, a regular slots player might put two-and-two together after observing an experienced AP winning. After all, most casinos are typically open to the public.

Another aspect of the team approach is the distraction it can provide. As mentioned previously, card-counting has a rich history. In the early days, one of the difficulties with card-counting was casino recognition from past winning sessions.

What was the card-counting APs response? Disguises. With modern casinos and a requirement for government-issued IDs, disguising an individual is very limited unless you happen to have an identical twin.

But you could explain the advantage play you’ve figured out to a team of trusted individuals, perhaps family members. They could then perform the advantage play for a pre-determined profit share.

Understanding Advantage Play Slots #3: Modern Casinos

With modern-day casinos and gaming regulations, slot machine advantage plays have undergone a sea change. It’s no longer possible to drop coins with a complicated pattern, which might cause a win, if that advantage play ever worked in the first place.

Using terminology from the Ocean’s 13 movie, a “Susan B. Anthony” con doesn’t matter any longer because U.S. casinos no longer use coin-operated slot machines. But that doesn’t mean advantage plays no longer exist. It means they’ve changed with the times.

Around 2012, slot machine manufacturers started offering operating systems to help casinos handle larger crowd sizes with ease, efficiency, and a smaller workforce. One of these innovations was a central computer server hardwired to every slot machine.

How To Beat A Modern Slot Machine

With it, casino operators could reduce their army of slots mechanics to a much smaller, and therefore cheaper, group. Instead of the mechanics changing the odds of winning every one to two weeks as needed to meet state gaming requirements, the computer server could do it electronically several times a day.

In this way, the casino saved money in two important ways: a smaller workforce devoted mostly to machine maintenance and a vast improvement in their ability to meet financial performance metrics from multiple weeks to several times daily.

Yes, slot machines still operate randomly under these new casino operating systems. But because the odds of winning can be remotely adjusted several times daily. Therefore, the odds of winning, while still random, are different before and after. And one is better than the other.

The task of the modern-day slot machine advantage player is to figure out which is which. Are the best odds in the morning, afternoon, or evening? Is it on busy days at the casino or non-busy days? On a holiday evening or the morning day after a holiday?

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Modern casino operating systems have much more excellent control over slot machines than ever. While this slot machine control is by a computer, the computer is itself controlled by humans. And humans love to tinker. And humans also make mistakes.

Rather than explain my winning slots strategies based on casino business practices here, I’ll refer you to my many website articles and podcast episodes on that topic.

Sooner or Later, Advantage Plays Stop Working

The types of advantage plays are effectively endless, but they all have one common disadvantage: Sooner or later, they stop working. Why? Because sometimes an advantage play is a disadvantage for someone or something else.

If a business practice is an advantage play, or even if it’s going too well, it’s not uncommon for that business to shut it down. Sometimes, there’s also a time limit on how long it lasts, making it more of a promotion than a business practice.

Because individual advantage plays stop working eventually, successful APs keep working on the next advantage play. For APs, figuring out advantage plays is a never-ending process.

But, as with most situations, there’s an advantage play for this, too. Some advantage plays go unnoticed because they are not dramatic. Any disadvantage to the casino is so small that it goes unnoticed.

Put another way the weakest advantage plays last the longest. One massive jackpot would be wonderful, but does it matter if it takes a year or two to make the same gaming profit at a much less noticeable level? Being less noticeable now is better for future advantage plays.

Some advantage plays are a change in perspective. Casino operators see a reduced workforce and daily performance metrics as their advantage play. That some modern APs, such as myself, have turned those business practices on their head doesn’t matter.

As I’ve previously mentioned, advantage players consider the time and cost of an advantage play versus its potential profit. As advantage players, casino operators make these same calculations with their millions or billions of dollars in gaming revenue.

As with card-counting, casinos adapted to players using that advantage play. In return, card counters wore disguises. Then casinos added more decks. Players figured out the math for using packs of decks.

And so it went, back and forth, until we now have casino surveillance of card games pattern recognition, automatic shufflers of a large number of decks, or even infinite decks,

Slot machine advantage plays, although more secretive, have already had to deal with counter-responses from casinos. While casinos had good business reasons to switch over from coins to ticket-in, ticket-out readers, doing so had a major impact on coin drop sequence advantage plays, whether they were effective advantage plays or not.

Modern slot machine advantage plays which currently work will stop working because casinos will develop counter-measures or change their business practices for some other reason. They do that, you know.

I’ve seen this happen. For me, some significant advantage plays went away after nine months. But I responded by figuring out the next advantage play. That’s what all APs, modern or not, do.

And maybe the new slot machine advantage plays I’ve figured out and used successfully, my winning slots strategies, will work at other casinos for you. I’m sharing them for two reasons. First, I have a (well-paid aerospace engineering) day job, which prevents me from using my winning strategies elsewhere, outside of an occasional weekend getaway.

Second, I’m doing that thing which APs do. I’ve determined that it is an advantage play to share this information with you. With enough time and effort, there is a potential profit in serving a community of slots players. I hope so, anyway. I’ve got massive student loans to pay.

Summary of Understanding Advantage Play Slots

Advantage plays have always been a bit mysterious because sharing them is counter-productive to winning at slots when using them.

But sharing is caring, so I’ve written this article on understanding advantage play slots from a modern-day perspective.

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Have fun, be safe, and make good choices!
By Jon H. Friedl, Jr. Ph.D., President
Jon Friedl, LLC

Gambling is a billion dollar industry that attracts millions of people around the world. While games such as Texas Hold ‘Em poker receive more fanfare, by far the most profitable and available attraction in these casinos is the slot machine. While familiar in appearance, these devices are a mystery to the layperson. Dating back to the late 1800s and with a history rooted in the California Gold Rush, “slots” use the principles of probability and chance to beguile players and create a profit for owners. The design of slot machines has evolved from mobile mechanical parts to mostly electronic components over the course of the last century, but their charm and attraction remain strong. With the advent of computer servers and live streaming of data, slot machines are poised to intrigue and befuddle a new generation of gamblers hoping to hit the jackpot.


The gambling industry brings in billions of dollars every year all over the world. Places such as Las Vegas and Monte Carlo have built their reputations on gambling establishments with hundreds of games ranging from poker to electronic horse racing and with all kinds of luxurious accoutrements from flashy shows to nightclubs. People travel from many different places, sometimes bringing a month’s worth of savings, so that they can participate in these games of chance and experience the casino atmosphere. More often than not, they leave having lost more money than they have won, but having enjoyed the experience nonetheless.
Since its introduction in 1893, the most popular form of gambling has been the slot machine. Slots are simple, giving rewards when the correct combination of symbols has surfaced. They rarely cost more than five dollars and require only the push of a button or the pull of a handle to play. Flashing lights, exciting sounds, and large grand prizes entice players who hope to strike it rich. Because they do not require skill or practice to play, these machines give everyone the chance to win. Immortalized in movies such as Casino and Ocean’s 11, slot machines continue to be the most profitable game in any casino. In Las Vegas alone, slot machines accounted for 67% of total casino profits in 2006 [1].
Various models of slot machines are in use today, but the most popular contains a combination of electronic and mechanical parts. Using the fundamentals of probability, slots are uniquely engineered to appear simple while disguising their true inner workings from the public. The slot machine combines engineering acumen, mathematical know-how, and psychological deceit in a single, attractive package.


In San Francisco in 1893, Gustav F.W. Schultze invented a small countertop gambling machine to capitalize on the strong gambling tendencies that resulted from the Gold Rush. This device accepted a nickel, which caused a colored disk to begin spinning. After the disk stopped, a connected star wheel determined the payout. A slide then cut the correct number of coins and dropped them into a payout cup. During the late 1890’s, Charles Fey perfected this machine by adding three wheels instead of one and changing their orientation so that they flashed symbols of playing cards through a window. Using more springs, cams and levers, Fey contrived a mechanism that allowed the reels to stop in succession, creating an atmosphere of suspense [2]. With over a thousand different possible combinations and a 75.6% payout of money played (meaning the owner kept 24.4%), Fey’s contraption known as the “Bell” became the standard archetype for slot machines and a popular attraction in saloons.

Herbert S. Mills further perpetuated the popularity of the Bell machines. By increasing the reliability and decreasing the cost of manufacturing slots, Mills was able to ship these machines throughout the new territories of the United States. He also pioneered the inclusion of a pack of gum with play in order to skirt the growing number of laws restricting the use of these gambling attractions. In essence, gamblers could only play once they performed the legal transaction of “buying” the gum. In 1906, Mills introduced his own slot machine with the now-classic bell and other symbols (Fig. 1) supplanting the original card signs on the slot reels [2]. Furthermore, he expanded the window opening from one to three lines to add another factor to entice people to play, as players could now see how close they were to winning.

Slot innovation continued in the twentieth century. During the 1920s, slots were revamped to accept quarters and even silver dollars. Sometimes skill elements were added, such as buttons that allowed the player to attempt to stop each specific reel at a moment of his or her choosing. Most importantly, the concept of the jackpot was incorporated. Windows showing a buildup of coins proved to be effective bait for many players.
In 1963, Bally Manufacturing Company introduced the first electronic slot machine. Electromechanical sensors replaced the mechanical slides and allowed for brand new features. All three lines in the slot window could offer payouts, as well as diagonal matchups, allowing for many more winning combinations [2]. Furthermore, multiplier machines could accept multiple coins for larger prizes. Soon, logic cards and integrated circuits replaced the switches and wires. In 1981, Michael S. Redd founded International Game Technology (IGT), a public company that pioneered a radical new invention in slots. Redd took all the recent electronic breakthroughs and coupled them with a computer that replaced the original wheel randomizer. This computer generated random numbers that instantly decided the payout and where each “reel” would stop. A motor simultaneously carried out these directions on the slot screen. These machines remain the basis for slots in today’s casinos.

The Modern Electronic Reel Slot Machine: A Piece by Piece Breakdown

Slot machines produced today are a far cry from their mechanical ancestors. Computer chips have replaced spinning wheels, and electronic credits have replaced coins. This fusion of new age electronics with old fashioned nostalgia creates a machine that, while simple in theory, beguiles players on a regular basis.
At the heart of all modern slot machines is a computer chip called the Random Number Generator (RNG). This device replaces the original spinning wheel found in gambling machines from the first half of the twentieth century. The RNG is capable of continuously generating thousands of random numbers and, in the case of the three-reel slot, thousands of three-number combinations every second [3]. Each of these three numbers in the combination serves to designate where the reels will stop.

To simplify the thousands of combinations into discrete slots on reels, each random number in the combination is divided by a set value (typically, slot machines use 32, 64, 128, 256, or 512 as that value). The computer records the remainder of this quotient, which by mathematical law cannot exceed the set value [4]. The remainder is mapped to a certain symbol that is physically distributed among the number of slots the reel contains. A virtual representation of this mapping using a set value of 128 and a reel with 22 slots may be seen in Fig. 2.

This is how the odds swing in favor of the casino. The quotient remainders are not all distributed equally among the actual slots on the reel. Blank spaces are weighed heavily, as seen in the Percent Chance of Choosing Symbol column, as are those that have a lower payout. Furthermore, each of the three reels is weighted differently. For instance, the first reel is most likely to hit the jackpot slot, while by the third reel the likelihood is minuscule. Along with a heavy weighting to blank spaces surrounding the jackpot, this creates a “near miss” effect and keeps the player in suspense [3].
The RNG is part of a larger Computer Processing Unit (CPU) that controls other various functions of the slot machine. The basic functions include the Start switch, Max Bet switch, token or credit sensor, and RAM to store the various hit combinations, reel stops and payouts. Depending on the style of machine the CPU also may control the hopper, which stores tokens or coins, or the credit account of the player [5].

For a machine with actual spinning reels, once the random numbers have been generated, the machine uses a stepper motor to turn each reel and stop it at the predetermined point [4]. A stepper motor is an electromechanical device that uses electrical pulses to drive a shaft or spindle in discrete increments. These incremental movements are related to the frequency and sequence of the electrical pulses, allowing for total movement control [6]. If the machine only has a screen, then a piece of software animates a virtual spinning reel.

Overall, the slot machine’s actions are controlled by a simple algorithm based on basic programming principles like IF switches and loops. The algorithm begins once the on switch is triggered (usually by the insertion of a token or credit). At this point, the start button or “lever” is pulled, which leads the RNG to choose the random numbers that will control the positions of the reels. The step motor simultaneously spins the reels until they arrive at the correct position. If the selected combination corresponds to a payout, many machines will trigger a program of flashing LED lights and sounds, and the payout will be awarded. Otherwise, the game ends, and the player must trigger the start switch once more by adding a new token or credit. In addition to this simplified loop shown in Fig. 3, some machines include special jackpots or other attractive motions and sounds in order to create a more satisfying experience for the gambler.

Slot-Machine Innovations

By today’s standards the technology employed in slot machines has not advanced very significantly. Fig. 4 shows some of these newer slot machines. The Random Number Generator central to the slot machine’s function has existed for decades. Even newer slots with more than three reels, multiple payout lines and interactive games are child’s play when compared with a current video game system. However, new innovations to the world of gambling games are cropping up and copying many existing prototypes of networked machines.

Modern Slot Machine Repair

In recent years, slot machine designers have worked closely with video game architects in order to bring some of the visual appeal found in virtual gaming to the gambling arena. Video monitors, 3D graphics, and group competition are all making their way into slot construction [7]. Furthermore, slots have taken on a pop culture persona in order to keep up with a younger generation of gamblers. Games featuring “Lord of the Rings” and “Sex and the City” themes have already appeared at gaming expos. Designers have even added multi-level games to help bring gamblers back.

One of the most intriguing developments in slot technology involves connecting slots to servers, much as office computer networks are designed. This innovation would allow casinos to easily manage minimum bets, percentages paid, and the type of game available on a machine. Furthermore, these activities or factors could be adjusted based on the time of day, level of activity at each floor, or even the players’ personal information [8]. These networks will also allow different games to be recommended for different players as well as the streaming of live television to built-in screens.

The appeal of slots has always been the atmosphere of suspense it creates with its spinning reels coupled with the appeal of “easy” money. The average person can easily set the minimum bet and playing is as simple as pressing a button. Recently, slot machines have been overshadowed by other table games such as poker, which is extensively televised, and the live excitement of craps. Changing with the times and utilizing new technologies will allow popular gambling machines from the past to remain as attractions to new generations of gamblers.


Modern Slot Machines For Sale

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    • [3] Michael Bluejay. “How Slot Machines Work.” Top Ten Las Vegas Tips. n.d. Web. 16 Jul. 2010. <http://vegasclick.c​om/games/slots/how-t​hey-work.html>.
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    • [5] Haruo Inoue. 1997. Slot Machine. U.S. Patent 5,609,524, filed July 12. 1995, and issued March 11, 1997.
    • [6] “Stepper Motors.” Omega Engineering Web. 16 July 2010. <​m/prodinfo/stepper_m​otors.html>.
    • [7] Christopher Palmeri. “Face-lift for the One-Armed Bandit.” Business Week 21 Dec. 2009: 77. Web. 15 July 2010. <http://www.thefreel​​+FOR+THE+ONE-ARMED+B​ANDIT-a01612094149>.​
    • [8] Quentin Hardy. “Well-Armed Bandits –” Forbes Business News. 19 May 2008. Web. 16 Jul. 2010. <http://www.forbes.c​om/global/2008/0519/​054.html>.
    • [9] “Old Downtown Las Vegas History.” EarlyVegas. n.d. Web. 20 Jul. 2010. <http://www.earlyveg​​>.
    • [10] Rusman. “Playing in an Online Slot Machines for Players.” Games and Entertainment Reviews. 6 Aug. 20101. Web. 11 Oct. 2010. <http://www.komiks-d​​playing-in-an-online​-slot-machines-for-p​layers.html>.
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