Question of the Day - 07 May 2021

After a program is approved (and a copy is kept) by Gaming Control, there is no need to use EEPROMs.  There may be a few around, but programs generally are burned on just plain (cheaper) ROMs.

Also whatever the game is (reel spinner, video poker, et.al.,) there are already several programs on the ROM with varying return percentages.  As an example, a poker machine may have 9/6, 9/5, 8/5 JOB among the games.  The slot dept chooses what game and denom it wants available for the player.  The game library chip (ROM) is rarely exchanged.

True, it would take a lot of time to change the return % on a group of machines, but it wouldn't involve the hardware.  The time would be in the paperwork that the Slot. Dept. would want, to record the machine results before/after making a new game configuration.

s an example of something I've observed several times: I was playing a machine in a Colorado casino, and the slot tech was activating the machine next to me. He accessed a menu that contained all the parameters you mentioned, INCLUDING payback percentage. The submenu contained six choices ranging from 90.3% to 97.1%. These were obviously available with the same EPROM chip, since he didn't fiddle with the innards of the machine--he only entered his choices on the menu.

I've seen something similar many times, though never with such close and detailed observation--this slot tech obviously didn't care what I saw. It makes sense that payback percentages can be altered this easily. There would be no reason for slot machine manufacturers to require their customers (the casinos) to perform a full lobotomy on the machines every time they wanted to modify the payback %.

As to why and how often they would make these changes--different question. But I maintain they can do so very easily.

My machines all have 2 Compact Flash cards one is the OS and the other is the game. On initial setup you select the payback along with other options and it is set. If you want to change the payback % you have to use a Clear card and it wipes everything from the computer and you start all over. This takes anywhere from 8 to 15min per machine.
My machines are WMS but IGT and others are pretty similar.

Most machines are not server based games.  Some may be SSGs (Server supported games), but that's not even the norm.  In an SSG, the program is downloaded onto a machine, and remains there until deleted or removed, much like a physical Eprom chip.  Each of the eproms have multiple game programs that can be changed, but the changes have to be documented, and if a total program change is made, the machine has to be recorded as a new machine in the slot database.  It is NOT common to change these programs out...too labor intensive.  Eproms have been replaced with other media (thumb drives, etc), but the functions are still the same.  Quit worrying about management shifting their game percentages on the fly...it can be done with the few SBGs out there, but the game has to be taken out of service first for (IIRC) 5 minutes, so it's not really worth the effort to do so with the documentation that is required.  Also, SBGs require more regulatory stuff.

Frank Legato is the author of the book How to Win Millions Playing Slot Machines! ... or Lose Trying, founding and contributing editor of Strictly Slots magazine, managing editor of Global Gaming Business, and contributing editor to Casino Player magazine.

He tells us, “In the case of single games, the hold is changed by switching out the EPROM chips."

EPROM stands for Erasable Programmable Read Only Memory. They're the microchips that determine the theoretical return of slot machines. They do this by setting the machine's winning combinations and defining the paytable -- in other words, which symbol combinations are winners and how much they pay. Slot-department managers/directors can change the hold percentage by physically replacing the EPROM chip. 

In the case of a server-based setup, with which slot managers can change a slot machine's hold percentage remotely via software, Legato says, "That's rare. The idea never took off. But yes, they can also change the program remotely.”

As for notifying regulators of any change in a slot machine's hold percentage, that's not required in Nevada. The Nevada Gaming Control Board’s Michael Lawton tells us, “Changes to a slot machine’s hold percentage do not require GCB approval. Any changes to the par percentage would have to be documented and maintained by the licensee.” 

A par sheet lists all the details of a slot machine's operation: the game's reels and paylines, minimum-maximum wagers, payback percentage and hit frequency, plays per jackpot, jackpot amount, plays per bonus, etc. The par sheet enumerates the payout percentage of the machine, ensuring that the slot manager knows its "par result."

Veteran gaming regulator Richard Schuetz tells us, “I'm not aware of any such direct communication [about a casino needing to inform regulators of a change to a slot machines hold percentage]. Any change to a slot hold needs to be recorded in the property's internal control documents, to which regulators have access. Also, monthly reports show the actual hold for different categories of machines. Any requirements that insist on advance notice [of a change] would be news to me.”

All of which means that, yes, if a casino wants to open with loose slots and then tighten them, it can be done, although it would involve a lot of leg work changing out all those EPROM chips. 

It's our understanding that in actual practice, the EPROM chips aren't changed very often. For any given casino, there is some optimal return, based on its customer base and profit stance. Wherever that is, a smart slot manager generally finds that point, then leaves the EPROMS set to that return.