Slots today are much more sophisticated than they were in previous decades. The first reel-style slot machine, invented by Charles Fey in 1895, featured 3 individual reels with symbols like horseshoes and clovers. A jackpot was triggered when the player hit a Liberty Bell on each reel.
So even though I don't like slots, I am a sucker for the Wheel of Fortune slot machines. Love to play for a chance to spin the wheel. With that said, every time I see them at the airport before our flight home I am always intrigued to try my luck. The wife always tells me no, so I don't. Michael Gaughan has been granted the rights to operate slot concession at McCarran International Airport under the name Michael Gaughan Airport Slots, operating over 1,300 slot machines in all of the airport's terminals. The concession is licensed by the state as Michael J. Gaughan, Airport Slot.
Fey’s machines were quite popular and were soon found in saloons across the San Francisco Bay Area. He originally split revenues with the bar owners, but after one of his machines was stolen, and similar machines hit the market, Fey switched to renting or selling his machines.
Slot manufacturers like Mills, Jennings, Pace, and Watling came and went over the next 60 years. During that time the machines were found in bars and roadhouses across the United States. Similar machines were also popular in Great Britain and Germany.
In the US, most states eventually outlawed open-gambling, but the slots were tolerated in many locations until the late 1930s when Nevada was the only remaining state with legalized gaming.
Although machine styles and designs changed, the overall operation and mechanics of the slots did not.
A single cherry symbol usually paid 2 coins, while 2 cherry symbols paid 5 coins. An orange on all 3 reels usually paid 10 coins, while plums or bells paid as high as 18 coins. A jackpot was 150 coins, meaning a nickel machine paid a total jackpot of $7.50.
The machine automatically dropped 20 coins, and the remaining $6.50 was paid by an attendant.
The monster machines drew crowds, but Bally had an even more important change that revolutionized slots. Previous machines had used metal tubes and slides to make payoffs that ranged from 2 to 20 coins.
Bally’s new Money Honey machines changed all that, with sleek designed fronts that opened on a hinge and gave slot attendants the ability to fill an electro-mechanical hopper with coins.
The new process allowed players to hit larger payouts and be paid automatically as the hopper spun and dispensed jackpots, counting the payout as it went.
Just 15 years later, the gaming industry introduced computer-run machines to their customers. The new machines used computer motherboards and removable chips to change game parameters. The machines used now employ random number generators to ensure safety and fair payouts for huge jackpots that have reached more than $20 million.
The machines most popular in the early days of Las Vegas had 3 reels and symbols like cherries, plums, oranges, and bells. A standard slot had 20 symbols per reel, so the odds of hitting the jackpot were 8000 to 1.
Today, machines can have nearly unlimited combinations. In fact, the largest group jackpot is offered by IGT on their Megabucks machines.
Those machines have virtual reels with 368 possible stops. Each virtual reel has one jackpot symbol. 368 x 368 x 368 gives the player one chance in 49,836,032 spins to hit the jackpot. Yes, the odds are high, but so are the jackpots, often over $20 million.
Unfortunately, nearly every large group (or linked machine) jackpot has a payoff made over 25 years. What that means is that if the jackpot is $1 million, you get a check for $40,000 the day you hit the big one. Then, you get a check in the mail for the same amount annually for 24 years.
- Appendices
- Slots Analysis
- Miscellaneous
Introduction
The following table ranks the Las Vegas casinos according to the looseness of their video display reeled nickel slot machines. The returns are based on a sampling of five different types of machines. The data collected goes back as far as October 2001 so the information is a bit dated.
Las Vegas 5 Cent Slot Survey
| Rank | Casino | Average Return |
|---|---|---|
| 1 | Palms | 93.42% |
| 2 | Gold Coast | 92.84% |
| 3 | Sahara | 92.81% |
| 4 (tie) | Bourbon Street | 92.63% |
| 4 (tie) | Imperial Palace | 92.63% |
| 4 (tie) | Slots a Fun | 92.63% |
| 7 | Key Largo | 92.60% |
| 8 | Western | 92.57% |
| 9 | Ellis Island | 92.56% |
| 10 | El Cortez | 92.56% |
| 11 | Orleans | 92.56% |
| 12 | Circus Circus | 92.56% |
| 13 | Gold Spike | 92.55% |
| 14 | Fitzgeralds | 92.54% |
| 15 | Fiesta - Rancho | 92.53% |
| 16 | Arizona Charlie's East | 92.51% |
| 17 | Barbary Coast | 92.50% |
| 18 | Terrible's | 92.49% |
| 19 | Arizona Charlie's | 92.49% |
| 20 | Hard Rock | 92.47% |
| 21 | Town Hall | 92.47% |
| 22 | Longhorn | 92.47% |
| 23 | Riviera | 92.23% |
| 24 | California | 92.14% |
| 25 | Lady Luck | 92.10% |
| 26 | Nevada Palace | 92.06% |
| 27 | Plaza | 91.94% |
| 28 | Luxor | 91.92% |
| 29 | Paris | 91.92% |
| 30 | San Remo | 91.88% |
| 31 | Excalibur | 91.84% |
| 32 | Palace Station | 91.84% |
| 33 | Ballys | 91.82% |
| 34 | Las Vegas Club | 91.76% |
| 35 | Four Queens | 91.75% |
| 36 | Texas Station | 91.71% |
| 37 | Casino Royale | 91.67% |
| 38 | Boulder Station | 91.55% |
| 39 | Aladdin | 91.5% |
| 40 | O'sheas | 91.48% |
| 41 | Hilton | 91.40% |
| 42 | Boardwalk | 91.28% |
| 43 | New York New York | 90.99% |
| 44 | Horseshoe | 90.96% |
| 45 | Sam's Town | 90.89% |
| 46 | Santa Fe Station | 90.87% |
| 47 | Flamingo | 90.86% |
| 48 | Golden Nugget | 90.85% |
| 49 | Stratosphere | 90.8% |
| 50 | Tropicana | 90.71% |
| 51 | Golden Gate | 90.64% |
| 52 | Silverton | 90.57% |
| 53 | Main Street Station | 90.56% |
| 54 | Westward Ho | 90.40% |
| 55 | Fremont | 90.37% |
| 56 | Castaways | 90.36% |
| 57 | Monte Carlo | 90.24% |
| 58 | Stardust | 89.97% |
| 59 | Frontier | 89.91% |
| 60 | MGM Grand | 89.81% |
| 61 | Harrahs | 89.32% |
| 62 | Treasure Island | 89.32% |
| 63 | Mirage | 89.3% |
| 64 | Caesars Palace | 89.05% |
| 65 | Mandalay Bay | 88.87% |
| 66 | Rio | 88.72% |
| 67 | La Bayou | 88.26% |
| 68 | Mermaids | 88.26% |
| 69 | Bellagio | 87.42% |
| 70 | Venetian | 86.66% |
| 71 | Airport | 85.02% |
Excluded Casinos
The Suncoast and Rampart Casino in Summerlin do not allow playing slots and taking notes at the same time. I can not include any casino that prohibits the method in which I gather data.
Location Averages
The next table shows the average return by location.
Returns by Region
| Location | Average Return |
|---|---|
| Off strip | 92.07% |
| Downtown | 91.66% |
| Strip | 91.47% |
| Total | 91.74% |
The above sign can be found across the street from the Palms. Although I did the study Anthony Curtis published it in the LasVegas Advisor, which is how it become well known. The'...' in the sign encompases quite a bit of information,which was conveniently left off the sign. Actually the study only says that the Palms had the lowest nickel video slotsof the casinos surveyed in Las Vegas. The small print at thebottom says, 'Independent study conducted between November2001-February 2002 on Austin Powers, Fortune Cookie, Reel'em In, and Wheel of Fortune games. They left off LeopardSpots, and the study began in October.
Observations
There seemed to be no truth behind slot placement myths. Machines on the end of a bank did no better on average than those in the middle. There was also no correlation between return and proximity to such things as the main door, table game pit, high traffic areas, and low traffic areas.
Most casinos were very consistent in their slot returns.If one nickel machine had a return of x% then all others like it also returned x%. However some casinos did mix up loose and tight machines, most notably Treasure Island and the California casinos.
Methodology
A kind and anonymous source provided me with par sheets for the games in question. The EPROM (Erasable Programmable Read Only Memory) chip is what tells the machine the order of the symbols on the reel, in some cases how the stops are weighted, how much each winning combination pays, and any other pertinent information about how much the machine pays.It is up to the slot manager to select which EPROM chip to order according to the return percentage desired. On atypical game there might be about 8 different possible return percentages, ranging from about 85% to 98%.
Each of the different par sheets has five sets of distinct reels. On video display slots the stops are not weighted; in other words all stops are equally likely. The distribution of each symbol on each reel is what determines the theoretical return of the machine. For example a higher paying machine may have more of the higher paying symbols.
On the machine itself three consecutive symbols arevisible on five different reels. By comparing actualobservations of results to the par sheets it is possible todetermine which reels the machine uses, and thus which par sheet and which return. There are various three-symbol combinations that appear in at least one but not all par sheets. So if one of these combinations occurs on an actualmachine it narrows down the possible par sheets. By playingenough the player can narrow down the possible par sheets tojust one.
To help identify the unique combinations I wrote a computer program for each game, which had the exact reel order of all 5 reels of all the par sheets. The program then counted the number of par sheets with each possible three-symbol combination. If the number was greater than 0 and less than the maximum then that combination was identified along with the associated par sheets it belonged to.
It is then a matter of simply playing the game and comparing the outcomes to the list of partially unique combinations. It only takes about 5-10 plays per machine to narrow down the possibilities to just one par sheet.
The averages in the table are actually an average of averages. For each kind of machine at each casino I took an average return. Then I took the average of these averages over the five kinds of machines I tested for.
Slot Machine Definition
There is some confusion about what constitutes a 'slot machine' or 'slot.' My definition, and that of most gamblers, is a gambling machine with either actual spinning reels or video representations of the them.
People in the gaming business and regulators generally refer to a slot machine as any gambling machine, including reeled slots, video poker, video keno, video blackjack,etc.. For purposes of statistics both casino managers and regulators combine all the electronic gambling machines together. For example, the Slot Chart in Casino Player magazine and reports by the Nevada Gaming Control Board do not isolate just reeled slots but consider all electronic games a 'slot.' Therefore my return percentages should not be expected to agree with those reported by the casinos or regulators. As far as I know mine is the only source to isolate just the return of reeled slots.
Acknowledgements
I would like to thank Rob Feldheim for helping with the slot play and record keeping. Rob helped me with most of the casinos on the east side of town and part of downtown. I would also like to thank par Sheet Pete (not his real name)for providing the par sheets, without which this project would not have been possible.
![Vegas](https://ak1.ostkcdn.com/images/products/is/images/direct/11baf61452b6d115635c3a3bd1b135cb35f3e5aa/"Slot-machines-at-an-airport%2C-McCarran-International-Airport%2C-Las-Vegas%2C-Nevada"-Black-Framed-Print.jpg?impolicy=medium "Vegas")
Internal Links
Go to slot machine appendix3B (Jean/Primm slot returns).
Go to slot machine appendix 3D(Henderson slot returns).
Go to slot machine appendix 3E(Las Vegas quarter and dollar slot returns).
Go to slot machine appendix 3F(Montreal slot return).
Go back to slot machines.
External Links
The main-stream media has covered this study in depth. Here are links to some articles.
- Turning'em loose, an article that appeared in the Las VegasReview Journal on May 19, 2002, about the possible effectsof this study.
- One-Armed Bandit or Robin Hood?, an article by myself for Contingencies Magazine explaining the methodology, results, and weaknesses of the study.
- Play by the rules and the one-armed bandits will still win. Boston Globe article about slot machines, in which my Las Vegas survey is mentioned and my advice quoted. (cache)
Las Vegas Airport Slot Machines
