Editorial
Methodology
The basis of every calculation, the reference rules used per game, and how pages are updated.
Probability in casino games can be calculated in closed form because every possible outcome is known: fifty-two cards per deck, thirty-seven or thirty-eight pockets on a wheel, thirty-six combinations of two dice, and two hundred and sixteen of three. This page sets out the basis used for every figure in the guides.
Two things make one casino's figures differ from another's: the table rules and the payout table. Every table on this site therefore states the conditions behind its calculation, and every guide includes a section on the effect of rule variations.
Basis of Calculation
- Probability is taken from the number of possible outcomes. The chance of one number on a European wheel is 1 divided by 37; the chance of a total of 7 on two dice is 6 divided by 36.
- House edge is derived from expected value. Chance of winning times payout, less chance of losing, with the sign reversed. Bets with a partial tie result, such as dragon tiger, account for the loss of half the stake.
- Games with decisions assume optimal play. The house edge of blackjack and video poker is calculated on the assumption that every decision follows that variant's basic strategy.
- Machine games use published figures. The return of a slot machine cannot be derived externally because symbol weightings are not published, so the range in general use is given alongside the operator's stated figure.
- Rounding to two decimal places. House edge figures are rounded to two decimals, except where more detail is needed to show a difference.
Reference Rules per Game
Figures in the guides use the reference rules below, being the arrangements most commonly found. Variations outside the reference are covered within each guide.
| Game | Reference rules |
|---|---|
| Baccarat | Eight decks, 5% Banker commission, Tie paying 8:1 |
| Blackjack | Six decks, dealer stands on all 17s, blackjack 3:2, doubling after split allowed |
| Roulette | European wheel of 37 pockets; the American wheel and la partage are stated separately |
| Sic bo | The payout table in most common use; variations on totals are stated separately |
| Dragon tiger | Eight decks, a tie taking half the stake, Tie paying 8:1 |
| Texas Hold'em | Seven-card probabilities; the Ultimate Texas Hold'em variant is stated separately |
| Video poker | Jacks or Better on a 9/6 table at five credits |
| Craps | Payouts in general use, with 3-4-5 times odds |
| Keno | A draw of 20 numbers from 80, with a 10-number ticket as the example |
How Figures Are Presented
- Every table carries a
captionstating the conditions of the calculation, such as the number of decks or a specific payout. - House edge is stated against the initial bet, and where it differs, the edge against all money wagered is given separately.
- Expected cost per hour uses the number of rounds in general use for that game and states the figure applied.
- Monetary values are used as calculation examples and are not recommendations about stake size.
Updates
The date of the latest update appears at the top of every page and is included in the sitemap. Pages are updated when the rules or payout tables in general use change, when an error in a calculation is found, or when a section needs further explanation.
Content is not revised for any other reason. Wording changes that do not alter the information do not change the date of a page.
Frequently Asked Questions
Why is the slot machine house edge given as a range?
Because symbol weightings are not published, so the return cannot be derived externally. What is given is the range in general use, 92% to 98%, alongside whatever figure the operator states on the machine information page.
Do these figures apply to online games?
Generally yes, since the rules and payout tables are the same. The differences lie in the speed of play and in the reshuffle after every round, which affect exposure calculations but not the house edge per bet.
What if a casino's table rules differ from the reference?
The effect of rule variations is covered within each guide, for example the effect of a 6:5 blackjack payout or of the la partage rule in roulette. Readers can adjust the reference figure accordingly.