Slot Machine Par Sheets
Last update: March 2020My article on how slots work explains how the probabilities result in a specific payback. In brief, the frequency of the various symbols dictates how likely you are to line up the various winning combinations, and those probabilities married to the paytable determines the payback of the machine.
Every slot maker creates a "par sheet" that lists the symbol frequency and the paytable. This allows the payback to be calculated, and a programmer to write the computer code. Slot manufacturers guard these par sheets religiously, for no good reason. (We can analyze games like craps, roulette, and blackjack because we know how those games work, and people still play them anyway.) However, with some sleuthing I've been able to track some down several par sheets, and they're all listed here below.
While this data has largely been secret before my investigative efforts, it's not really a useful secret, from a player perspective. Knowing the reel stripping for any particular slot doesn't give you any kind of edge or help you develop any kind of strategy. If you're flipping a coin, you know the only possible outcomes are heads or tails, but that knowledge doesn't allow you to predict what comes next. The real value of these is for those who are creating their own slot machines.
List of Par sheets
- In the Money. A Bally game from 2000. First published in the 2005 edition of Casino Operations Management.
- Blazing 7s
- Red White & Blue. A 94.675% payback flavor.
- Red White & Blue. An 87.47% payback flavor.
- Double Diamond
- Phantom of the Opera
- Lucky Larry's Lobstermania
- Money Storm
- Generic 1987 IGT slot. This is from the 1998 edition of the book Casino Operations Management.
- Vamos a Las Vegas (VLV). A slot by the Wizard of Odds. This is a fake-money, online version (not a real-money slot).
- Bluejay Bonanza. This is the fictional machine I created to explain how slot paybacks are calculated. The article doesn't contain a par sheet per se, but the tables in the article contain the same kind of data that would go into a par sheet.
Play slots online
I suggest you play something other than slots because the slot odds are so bad. You could also play online with fake money, because then it doesn't matter if you lose. A good casino for free-play is Bovada, since it requires no download and no registration. (If you see a registration box, you can close it and continue without registering.) You can play with real money too, though I hope you won't (or at least won't bet more than you can comfortably afford to lose).
All my slot machine articles
- Slot machine basics. How much it costs to play, how much you can win, expected loss, why they're a bad bet, why they're popular, how you can limit your losses, speed of play
- How to play slot machines
- Slot returns. How much they pay back.
- The Randomness Principle. Slots don't continually get looser and tighter as they're played. They don't have to.
- How they work. Explains the randomness principle, and runs through the math to show how a game returns a particular payback percentage. There's a companion page on Par sheets.
- Slot Machine Myths
- Slot Machine B.S. Wrong info that's published elsewhere.
- Strategies. Tips for increasing your chances of winning, and saving money.
- Slot Jackpots. Odds of hitting the jackpot, progressive jackpots, and other jackpot topics.
- Skill-Based Slots. The scoop on the new games in which your results aren't entirely determined by chance.
- Slot Machine malfunctions. How and why slot machines screw up, causing players to think they've won the jackpot when they really haven't.
- Slot Machine Simulator. I programmed an exact replica of the Blazing 7s slot (odds-wise). Click it to play thousands of spins in one second and see how you do.