Sports betting glossary

A three-outcome market: 1 (home win), X (draw), 2 (away win), generally covering regulation time.

The reasoning and data — statistics, form, context — behind a prediction, before it is checked against the market.

A handicap that usually reduces a market to two sides; a .5 line rules out any refund, while a quarter line splits the stake across two neighbouring lines and can produce a half-win or half-loss.

A position that consists of betting for an outcome to happen, similar to a standard bet placed with a bookmaker.

Money set aside from your personal budget, dedicated to sports betting and tracked over time.

A platform that matches opposing positions (back and lay) between participants rather than setting its own price, and usually charges a commission on net winnings.

The sum of implied probabilities across all outcomes of a market — 100% with no margin, more once a margin is built into the prices.

The excess built into a market's prices: the sum of implied probabilities across all outcomes, minus 100%.

A classification crossing business model (sharp/soft) with price formation (market maker/follower), plus the distinct model of the betting exchange.

The "both teams to score" market, settled as Yes (each team scores at least one goal) or No (at least one team stays at 0).

The gap between the odds you took and the closing odds, expressed as a percentage: odds taken ÷ closing odds − 1.

The last odds a bookmaker offers before kick-off, used as a reference to measure the quality of a price taken earlier.

The cut a betting exchange takes from a winning bet's net profit, which must be factored into any comparison with a bookmaker's price.

A market that requires picking a match's exact final score, usually priced high because of the large number of possible outcomes.

A three-selection market (1X, 12, X2), each covering two of the three outcomes of a 1X2 market, priced lower than the matching 1X2 bet.

A bet on one team where the stake is refunded, rather than lost, if the match ends in a draw.

The decline of a bankroll from its most recent peak, measured in absolute value or as a percentage of that peak.

A whole-number handicap applied to the final score, which keeps three outcomes — handicap win, handicap draw and handicap loss.

The theoretical average outcome of a decision repeated many times: (estimated probability × odds − 1) × stake.

Odds derived from a probability estimated independently of the market: 1 ÷ estimated probability.

An operator that aligns its odds with one or more reference bookmakers rather than building them itself.

Stakes collected minus winnings paid out to bettors; the regulatory measure of an operator's revenue, before costs and taxes.

An artificial adjustment to the score, margin or total used to settle a betting market.

The total amount of money wagered by bettors with an operator over a given period.

The probability derived from a decimal price: (1 ÷ odds) × 100, margin included.

A position that consists of betting against an outcome: the layer keeps the backer's stake if the outcome does not happen, but must pay the backer's winnings if it does.

The maximum amount a layer can lose if the outcome they bet against happens; calculated by multiplying the backer's stake by the odds minus 1.

The reference value of a totals or handicap market (the 2.5 in Over 2.5, the -1 in a handicap), against which a selection is compared for settlement.

The amount available to be matched at a given price, notably on a betting exchange — a displayed price is not always available for any stake size.

A betting category offered on an event (1X2, over/under, handicap…), which defines the possible outcomes and how they are settled.

A bookmaker that builds its own prices rather than copying them from other operators.

An odds movement that combines several notable features — intensity, speed, timing, consensus, consistency — without being a prediction.

The market on the match winner, usually with two outcomes and no draw.

What remains for an operator after costs, taxes and other expenses, once gross gaming revenue has been calculated.

The odds obtained after redistributing a market's overround across its outcomes, through proportional normalization or an equivalent method.

The probability obtained after redistributing a market's overround across its outcomes — an estimate, not the true probability of the outcome.

The price an operator displays for a given outcome, expressed in one of the three usual formats — decimal, fractional or American.

Three ways of writing the same price: decimal (total return per 1 staked), fractional (net gain) and American (gain per 100 staked, or stake needed to win 100).

A totals market: betting above (Over) or below (Under) a line, on a total of goals, points or games.

The part of the book percentage above 100%, corresponding to the margin a bookmaker builds into a market's prices.

also known as: vig, vigorish

An argued opinion on a match's outcome, distinct from the analysis and data behind it.

The share of stakes an operator actually keeps once every bet is settled, as opposed to the theoretical margin shown at the moment of pricing.

The possibility that a bankroll runs out before reaching a goal, depending on starting capital, stake size and variance.

The observed return on settled bets: net profit ÷ total amount staked × 100.

The number of decisions needed for a betting record to become meaningful — depends on the odds played, the assumed edge and the variance.

Markets more specific than a main market — corners, cards, goalscorers, player stats, time-based markets, team totals.

The precise choice made on a market — Over, a team, an outcome — distinct from the market itself, which defines the set of possible choices.

Two informal business models: sharp bookmakers run low margins and accept informed bets as a signal; soft bookmakers target the general public with higher margins and promotions.

A fixed fraction of a bankroll used as a betting reference, so each bet stays proportional to the capital at risk.

A fast, visible odds movement that hits several bookmakers and spreads across the market.

The gap between an independently estimated probability and the probability the offered odds would require — positive when the estimate exceeds that requirement.

also known as: edge

A sum of implied probabilities below 100% on a market, possible by combining the best odds from several bookmakers.

A bet whose estimated probability exceeds what the offered odds require: edge = estimated probability × odds − 1.

The spread of observed outcomes around a theoretical expectation, wider when the odds played are high and the sample is small.

A statistical measure that estimates, from the quality and position of chances created, how many goals a team should have scored on average. An input for analysis, never a guaranteed outcome.