Glossary: provably fair and casino math terms
38 terms used on BetProof, each explained in a few plain sentences and linked to the page where it is put to work.
Fairness and verification terms
Provably fair
A way of running a game so that each result can be recomputed by the player after the round. The casino commits to its secret value in advance and reveals it later. The fairness verifier does the recomputing.
Server seed
The secret value chosen by the game or the casino. It is shown only as a hash while in use and revealed afterwards, which is what makes a check of a finished bet possible.
Client seed
The value that comes from the player side and is mixed with the server seed. Because the casino cannot know it in advance, it cannot shape the result. In Aviator the first three players of a round supply it. You enter it in the verifier next to the server seed.
Nonce
A counter that goes up by one with every bet on the same pair of seeds. It makes each bet produce a new result without changing the seeds. It is the third value the result verifier asks for.
Hash
The fixed-length fingerprint of a piece of data. The same input always gives the same hash, and the input cannot be worked out from it. The Aviator verifier shows the hash of a round next to its result.
SHA-256 and SHA-512
Two standard hash functions. Many games publish a SHA-256 hash of the server seed, and Aviator turns a SHA-512 hash of its seeds into the multiplier, as the Aviator verifier shows step by step.
HMAC
A hash computed with a key. In the common dice scheme the server seed is the key and the client seed with the nonce is the message. The result verifier uses HMAC-SHA256 for its generic method.
Seed rotation
Replacing the current server seed with a new one. The old seed is revealed at that moment, and all bets made on it can then be verified.
Bulk verification
Checking a whole list of finished rounds in one go instead of one by one. The bulk verifier recomputes every row and marks the ones that match.
Fairness panel
The window inside a game that shows the seeds, the hash and the result of a finished round. Without it a round cannot be recomputed. The Aviator page shows where to find it and what to copy.
Return, edge and risk terms
RTP (return to player)
The share of all stakes that a game pays back over a very long run, written as a percentage. A game with an RTP of 97% keeps 3 of every 100 wagered on average. The edge comparison sorts every title of a type by it.
House edge
The share of each stake that the casino keeps on average: 100% minus the RTP. It is the price of a bet, and the expected loss calculator turns it into an amount.
Expected loss
The average cost of a session: turnover multiplied by the house edge. It is an average, not a forecast for one evening. See the expected loss calculator.
Turnover
The sum of all stakes placed, counting money that was won and bet again. A hundred bets of 10 are a turnover of a thousand, whatever the balance did in between. It is the first input of the expected loss calculator.
Variance
How far results spread around the average. Two games with the same RTP can feel very different when one pays small wins often and the other large wins rarely. The strategy simulator shows the spread over thousands of runs.
Volatility
The label a provider puts on the variance of a game, from low to very high. It describes the ride and not the price. The full game list on a casino page is where BetProof reads it from: the lobby of the casino.
Losing streak
A run of lost bets in a row. Streaks that look impossible are a normal part of long sessions, and the losing streak calculator gives their exact chance.
Bankroll
The amount set aside for play. How long it lasts depends on the stake, the odds of the bet and the house edge, which is what the bankroll survival calculator works out.
Risk of ruin
The chance that a bankroll runs out before a given number of bets has been placed. It grows with the stake and with the length of the session. The bankroll survival calculator puts a number on it.
Martingale
A staking plan that doubles the bet after every loss. It wins small amounts often and loses a large amount rarely, and it does not change the house edge. Try it in the strategy simulator.
Stake
The amount placed on one bet. Every figure "per 100 wagered" on this site is the sum of stakes, whatever unit they are in. The unit converter translates a stake between crypto units and your currency.
Satoshi
The smallest unit of Bitcoin: one hundred millionth of a coin. Crypto bet sizes are often shown in satoshi or in mBTC. The unit converter translates between them.
Terms used inside the games
Multiplier
The number a winning stake is multiplied by. A multiplier of 2.00x returns twice the stake, the stake included. The crash calculator shows how often any multiplier is reached.
Crash point
The multiplier at which a crash round ends. It is fixed before the round starts and nobody outside the game can see it in advance. More on the Aviator page.
Cash-out
Taking the current win and leaving the round. In a crash game it has to happen before the crash point. The Aviator page shows how often each cash-out target is reached.
Paytable
The table of what a game pays for each outcome. Together with the odds of each outcome it fixes the RTP. The plinko calculator shows a paytable we read from a game and the return it produces.
Max win
The largest multiplier a game can pay. The larger it is, the rarer it is. The max win calculator gives the chance and the average wait.
Demo mode
A version of a game played with play money. It shows the rules and the pace without risk. The casino page says how many titles in the lobby offer one.
Reduced RTP version
A configuration of a game that pays back less than the standard version, offered by the provider to casinos. The game looks the same. The casino page lists the titles that run in such a version.
Game provider
The studio that makes a game and runs its rounds. The provider sets the RTP options and decides whether seeds are shown. The casino page lists the providers with the most titles.
Lobby
The list of games on a casino site, usually split into categories. BetProof reads the RTP and the other figures of each title from there. The casino pages give the date of each reading.
Wagering
Betting a bonus amount a set number of times before it turns into real money. Not every game counts towards it. A casino page on BetProof gives one figure about it: how many crash and instant titles count.
Betting odds terms
Decimal odds
A betting price written as the total return on one unit staked, stake included. A price of two means a winning stake comes back doubled. The odds converter shows the same price as a fraction and in American form.
Implied probability
The chance a price stands for: one divided by the decimal odds. It includes the cut of the bookmaker, so it runs above the true chance. The converter for betting odds works it out from any format.
Bookmaker margin
What the implied chances of all outcomes add up to above one hundred percent. It is the average share the bookmaker keeps, the betting counterpart of the house edge. The margin calculator finds it from the prices of a market.
Fair odds
The price an outcome would carry with the margin taken out, so that the chances of all outcomes sum to exactly one hundred percent. The calculator for margin and fair prices lists it for each outcome.
Kelly criterion
A rule for stake size: bet the share of the bankroll equal to your edge divided by the profit per unit. With no edge it stakes nothing, which is the case in every casino game. The Kelly stake calculator applies it.
Arbitrage
Covering every outcome of an event at prices from different bookmakers that together leave a profit whichever one wins. It is also called a sure bet. The arbitrage calculator checks the prices and splits the stake.