Glossary
The odds-data vocabulary, defined.
Plain-English definitions for the terms a data buyer meets: odds API, oddsmatcher, lay odds, qualifying loss, arbitrage versus value, and more. Each links into the coverage it describes.
Odds data & APIs
- Odds APIAn odds API is an interface that delivers bookmaker and exchange prices as structured data your software can read, instead of scraping betting sites yourself.
- Odds feedAn odds feed is a continuously-updating stream of bookmaker and exchange prices delivered as structured data for a product to consume.
- Odds dataOdds data is the structured prices and market information from bookmakers and exchanges that powers comparison, matched-betting and arbitrage products.
- Normalised oddsNormalised odds are prices mapped to consistent selections, markets and formats across books, so they can be compared like for like.
- Odds comparisonOdds comparison shows the best available price for a selection across many bookmakers, helping users find value and helping sites monetise.
- In-play oddsIn-play (live) odds update during an event. OddsRelay is built for pre-match data, not in-play streaming.
Matched betting
- Matched feedA matched feed delivers bookmaker back prices already paired against exchange lay prices, so a product skips building its own matcher.
- OddsmatcherAn oddsmatcher pairs bookmaker back prices with exchange lay prices and rates them, so a matched bettor can find the lowest-risk qualifying bets.
- Matched bettingMatched betting is a technique that uses bookmaker promotions and exchange lay bets to extract value at low risk, by covering both sides of an outcome.
- Qualifying lossQualifying loss is the small, expected loss from placing a matched back-and-lay bet, before any free bet or promotion value is added.
- Best odds guaranteed (BOG)Best odds guaranteed is a racing concession that pays the larger of your taken price and the starting price if it drifts in your favour.
- Extra placeAn extra-place offer pays out on more finishing positions than the standard each-way terms, creating matched-betting value in racing and golf.
- Each-way betAn each-way bet is two bets in one (a win part and a place part), central to racing and large-field golf betting.
- Free betA free bet is a bookmaker token that stakes a bet without risking your own money, usually returning winnings minus the stake. Free bets are the engine of matched betting.
- Starting price (SP)The starting price is the official odds of a horse or greyhound at the off, used to settle bets without a taken price and central to best-odds-guaranteed.
Arbitrage & value
- Arbitrage (surebet)Arbitrage, or a surebet, is when prices across books or the exchange let you cover every outcome for a guaranteed-in-theory margin.
- SurebetA surebet is another name for an arbitrage: a set of bets across books or the exchange that covers every outcome for a locked margin.
- MiddleA middle is a bet on two sides of a handicap or totals line where a range of results wins both, with the rest losing only the margin.
- Value bettingValue betting backs prices that are higher than their true probability implies, winning over the long run rather than on any single bet.
- Expected value (+EV)Expected value is the average profit or loss a bet would return if repeated many times. A positive-EV (+EV) bet wins over the long run.
- Value betting vs arbitrageArbitrage locks a guaranteed-in-theory margin by covering all outcomes. Value betting takes prices that beat fair odds and profits over the long run.
- DutchingDutching backs several selections in the same market across books so that any of them winning returns the same profit, which is useful where there is no exchange.
- Bankroll managementBankroll management is sizing each bet relative to your total funds so variance does not wipe you out before an edge plays out.
Exchanges & laying
- Lay oddsLay odds are the prices at which you can bet against an outcome on a betting exchange, the foundation of matched betting and arbitrage.
- Back betA back bet is the conventional bet that an outcome will happen, the opposite of laying it on an exchange.
- Betting exchangeA betting exchange is a peer-to-peer market where users back and lay outcomes against each other, rather than against a bookmaker.
- Exchange commissionExchange commission is the percentage a betting exchange charges on net winnings, in place of building a margin into its odds.
- LiquidityLiquidity is how much money is available to match at a given price on an exchange. Thin liquidity means a lay price may not be fillable in size.
- Cash outCash out lets a bettor settle a bet early for a value the bookmaker offers based on current odds, rather than waiting for the result.
Markets & pricing
- Implied probabilityImplied probability converts a price into the chance it represents. For decimal odds, it is one divided by the price.
- Overround (margin)The overround is the bookmaker's built-in margin: the amount by which the implied probabilities of all outcomes exceed 100%.
- Decimal oddsDecimal odds express the total return per unit staked, including the stake: 2.50 returns 2.5 times the stake.
- Sharp bookmakerA sharp bookmaker prices markets efficiently and accepts large bets, so its odds are a strong benchmark for fair value.
- Soft bookmakerA soft bookmaker prices more for recreational players and runs promotions, so its odds are often beatable, making it the target of value and matched betting.
- Closing line value (CLV)Closing line value measures whether you bet at a better price than the market's closing price, a strong long-run indicator of a real edge.
- Handicap bettingHandicap betting gives one side a virtual start in goals, points or games, turning a lopsided match into a near-even market.
- Asian handicapAn Asian handicap removes the draw with a fractional or split goal line, producing a sharp, low-margin two-outcome market.
- Accumulator (acca)An accumulator, or acca, combines several selections into one bet where all must win for it to pay out, multiplying the odds together.
- Bet builder (request a bet)A bet builder combines several markets within a single match into one priced bet. They are popular, promotion-heavy, and often priced less efficiently.
- Odds formats (decimal, fractional, American)Odds come in decimal (2.50), fractional (6/4) and American (+150) formats, all expressing the same probability, with decimal the cleanest for computation.
- Line movement (steam)Line movement is how a market's odds shift before an event as money and information arrive. A sharp, sudden move is often called steam.
- Price boostA price boost is an enhanced, above-market price a bookmaker offers on a selection to attract bets, and a frequent matched-betting and value target.
- Push (void)A push is a tie against the line (a handicap or totals bet that lands exactly on the line), so the stake is returned rather than won or lost.
- MoneylineA moneyline is a straight bet on which side wins, quoted in American odds. It is the US equivalent of two-outcome match odds.
- Sports spread bettingSports spread betting pays out proportionally to how right or wrong you are, unlike fixed-odds betting where the return is set when you bet.
- Steamer & drifterA steamer is a selection whose price is shortening (backed in). A drifter is one whose price is lengthening (drifting out). They are the two directions of market movement.
Buying odds data
- Bet code (booking code)A bet code is a short reference that stores a bookmaker betslip so it can be shared or rebuilt. Bet codes are common across African books and central to bet-code converters.
- Odds API costWhat an odds API costs depends on coverage depth, update times, whether the data arrives matched, and the support behind it, well beyond the headline number.
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