Every term you'll encounter in sports betting, from odds formats and market types to staking strategies and bookmaker jargon — defined clearly in plain English.
A single bet combining 3 or more selections. All selections must win for the bet to pay out. Returns multiply with each leg, but so does the probability of failure. See: Singles vs Accas.
A result measured against the point spread rather than the outright winner. Used in US sports.
Simultaneously betting all outcomes of a market across different bookmakers to guarantee a profit. Requires the sum of implied probabilities to be below 100%. See: Arbitrage Guide.
A handicap betting format that eliminates the draw by applying fractional goal handicaps. A push (tie on the line) returns the stake. See: Handicap Guide.
Your total available betting funds. Managing it as a percentage rather than fixed amounts is fundamental to long-term sustainability.
Betting on an outcome to happen. The standard betting position (as opposed to laying on an exchange).
A platform where bettors trade against each other rather than a bookmaker. Betfair is the largest. Commission is charged on net winnings instead of a margin. See: Betfair Review.
A market betting on whether both teams will score at least one goal. Independent of the final result.
A feature allowing you to settle a bet before the event ends, at a value calculated by the bookmaker based on current market odds. Usually offered at a slight disadvantage to the bettor.
The final odds available on a market immediately before it closes. The closing line is the most efficient price — consistently beating it (closing line value) is the strongest indicator of genuine edge.
The difference between the odds you bet at and the closing odds. Positive CLV means you consistently found value, regardless of short-term results.
The fee charged by a betting exchange on net winnings, typically 2–5%. Replaces the margin built into fixed-odds bookmaker prices.
A market betting on the exact final scoreline. High-margin, high-variance markets.
When two or more selections finish equal in a market (e.g. joint winners in horse racing). Stakes are typically divided by the number of tied selections.
The most widely used odds format globally. Represents total return per unit staked, including the stake. Decimal 2.50 = 150% profit on a winning bet. See: Decimal Odds.
An accumulator containing exactly two selections.
A market where the draw result refunds your stake, leaving a two-outcome market. Different from Asian handicap in that it is typically offered on the 1X2 market with the draw removed.
Two bets in one: a win bet and a place bet (typically top 2, 3, or 4 depending on field size). Common in horse racing.
Your measurable advantage over the bookmaker. Defined by finding bets with positive expected value.
The average outcome of a bet over a large sample. EV = (P_win × profit) − (P_loss × stake). Positive EV bets are profitable long-term. See: EV Guide.
See: Betting exchange.
Odds agreed at the time of placing the bet, regardless of subsequent market movement.
Staking the same fixed amount on every bet regardless of bankroll size. Simple but suboptimal compared to proportional staking.
The traditional UK odds format. Shows profit per unit staked (not including stake). 6/4 means £6 profit for every £4 staked. See: Fractional Odds.
A promotional token that covers your stake if you win, but the stake itself is not returned with the winnings. See: Matched Betting.
When a bookmaker restricts your account, typically by limiting maximum stake amounts, following consistent winning. Common at soft books; Pinnacle and exchanges do not gub.
The description of ground conditions. Significantly affects performance and is a key variable in racing models.
A virtual advantage or disadvantage applied to a team or player to create a more level betting market. Asian and European handicap are the two main types. See: Handicap Guide.
Placing a bet on the opposite side of an existing wager to reduce risk or lock in profit, typically as odds shift in your favour.
An Asian format equivalent to fractional odds expressed as a decimal. Hong Kong 1.5 = fractional 3/2 = decimal 2.5. See: Asian Odds.
The probability implied by the bookmaker's odds. Calculated as 1 ÷ decimal odds. Bookmakers inflate implied probabilities above 100% to create their margin.
Betting placed after an event has started, while it is in progress. Higher margins, faster execution required. See: Live Betting Guide.
A format used in Southeast Asia similar to American odds but expressed as a decimal. Positive = profit per unit staked; negative = stake needed to profit one unit. See: Indonesian Odds.
US term for the bookmaker's margin. Typically –110 on both sides of a spread bet, meaning 4.55% margin per side. Also called vigorish or vig.
A mathematical formula for optimal bet sizing: f* = (bp − q) ÷ b. Maximises long-run bankroll growth. Most practitioners use half or quarter Kelly for safety. See: Kelly Guide.
On a betting exchange, selling a position — effectively acting as the bookmaker and paying out if the outcome occurs. Used in matched betting and trading strategies.
On a lay bet, the maximum amount you must pay out if the selection wins.
The current odds or point spread offered on a market.
Checking odds across multiple bookmakers before placing a bet to find the best price. See: Line Shopping Guide.
The amount of money available to be matched in a betting exchange market. High liquidity means fast, large bets at accurate prices.
A Southeast Asian format where positive numbers are profit per unit (like decimal − 1) and negative numbers indicate the stake needed to profit one unit. See: Malay Odds.
See: Overround.
Exploiting bookmaker free bet offers by placing a back bet at the bookmaker and a lay bet at an exchange, removing outcome risk. See: Matched Betting Guide.
US term for a straight win bet with no handicap. Displayed in American odds format.
Bets covering more than one selection, e.g. doubles, trebles, accumulators.
The price offered on an outcome. Represents the implied probability and determines the return on a winning bet.
The total of all implied probabilities in a market. A fair market = 100%; a 107% overround means a 7% bookmaker margin. Also called the book or vig. See: Margin Guide.
A market betting on the total of some measurable statistic (usually goals, points, or games) being above or below a specific line.
US equivalent of an accumulator. Multiple selections combined; all must win.
A statistical model used to predict the probability of a given number of events (e.g. goals) in a fixed interval. Standard tool for football modelling. See: Poisson Guide.
Synonymous with odds.
When a bet result lands exactly on the handicap or spread line, resulting in a stake refund with neither win nor loss.
The total payout from a winning bet, including both profit and returned stake.
Profit as a percentage of total amount staked. The primary long-term performance metric for bettors.
A sophisticated or professional bettor. Sharp books (Pinnacle, exchanges) are those that cater to and accept sharp action.
A recreational-facing bookmaker that offers bonuses and promotions but restricts winning accounts.
See: Point spread.
The amount wagered on a bet.
Rapid, sharp movement in a betting line driven by coordinated professional betting.
US market where you adjust a point spread in your favour in exchange for reduced odds. Available on NFL and NBA.
See: Over/Under.
An accumulator containing exactly three selections.
The fair-value odds for an outcome with no bookmaker margin applied. Found by removing the overround from quoted odds.
A bet where the available odds are greater than the true probability warrants. The only mathematically sound route to long-term profit. See: Value Betting Guide.
See: Juice.
A bet that is cancelled and has the stake refunded. Occurs on abandoned events, push results on Asian handicap lines, or market errors.
The principle that large-volume betting markets (like Betfair or Pinnacle's closing line) aggregate information efficiently, producing near-accurate probability estimates.
A football statistic measuring the quality of goal-scoring chances. Used as the primary input for over/under and Asian handicap models.