Reference
Betting glossary
Every term used on this site, defined once and in plain language. If something here is wrong or unclear, tell us — corrections are welcome.
Last reviewed August 2026
Terms
- Vig — also vigorish, juice, margin, overround
- The bookmaker's built-in cut. Add up the implied probabilities of every outcome in a market and the amount above 100% is the vig. It is why betting every outcome at one book loses with certainty, and why a raw price is not a probability.
- Overround
- The numerical size of the vig for a specific market: (Σ 1/odds) − 1. A 1X2 market at 2.10 / 3.40 / 3.90 has an overround of 2.67%. Sharp books run 2–3% on major markets; recreational books 5–10%, and far more on obscure ones.
- Implied probability
- What a price claims about an outcome's chance, found by inverting the decimal odds: 1/odds. Odds of 2.50 imply 40%. It always overstates the true chance, because the vig is still in it.
- De-vig — also no-vig, fair odds
- Removing the bookmaker's margin from a complete set of prices so the probabilities sum to exactly 100%. The result is an estimate of true probability and the break-even price beside it. Only meaningful on a sharp book's prices.
- Fair odds
- The break-even price for an outcome: 1 divided by its true probability. A bet has value above this price and not below it. Every value bet on this site is measured against a fair price derived from Pinnacle.
- Value bet — also +EV bet
- A price longer than the fair odds — one that pays more than the outcome's real chance justifies. Profitable on average over many bets, and entirely capable of losing any individual one.
- Expected value — also EV, edge
- The average return per unit staked: (true probability × decimal odds) − 1. A +6.67% edge means 100 staked returns an expected 106.67 across many repetitions of the same bet.
- Arbitrage — also surebet, sure bet, arb
- A set of prices across different bookmakers whose implied probabilities sum to under 100%. Backing every outcome in proportion returns more than was staked whatever the result. Typically 0.5–3%, and usually gone within minutes.
- Middle
- Two bets on different lines of the same market that can both win — backing over 2.5 at one book and under 3.5 at another wins both if exactly three goals are scored. Unlike an arbitrage the worst case is usually a small loss, in exchange for a large upside.
- Closing line value — also CLV
- How the price you took compares with the fair price the market closed at. Consistently beating the closing line is the standard evidence that an edge was real, and it produces a verdict in dozens of bets where profit needs hundreds.
- Kelly criterion
- A staking rule that maximises long-run bankroll growth: stake edge / (odds − 1) of your bankroll. Optimal only if the probability estimate is exactly right, so most bettors use a fraction — a quarter is common.
- Soft book — also recreational book
- A bookmaker whose prices are set partly to attract and balance its own customers rather than purely to be accurate. Wider margins, lower limits, and quick to restrict anyone who consistently beats the price — and, for the same reasons, where value is found.
- Steam
- A fast, sustained price move across the market, usually caused by informed money or news. A sharp book steaming toward your pick while the book you bet lags is the pattern most associated with a genuine edge.
- Price drop
- A shortening price — the market deciding an outcome is likelier than it thought. Tracked on the sharp line even for fixtures no soft book has priced yet, since it shows money moving before there is anything to bet into.
- Palpable error — also palp
- An obviously wrong price — a misplaced decimal, the wrong team. Bookmakers void them under their terms, which is why an implausibly large edge or arbitrage is a warning rather than an opportunity.
- Limited — also restricted, gubbed
- An account whose maximum stake has been cut, often to a trivial amount, because the bookmaker identified it as consistently beating the price. The practical ceiling on both value betting and arbitrage at soft books.
- Draw no bet — also DNB
- A two-way market where a draw refunds the stake. It is a function of the 1X2 prices rather than an independent market, so a book that has stopped maintaining it will quote a price its own 1X2 contradicts — a common source of fake edges.
- Asian handicap
- A handicap market that removes the draw by giving one side a goal head start, sometimes in quarter increments that split the stake across two lines. Quarter lines half-push, which makes them unusable for arbitrage.
- Betting exchange
- A marketplace where bettors take both sides directly, with the operator taking commission on net winnings rather than building a margin into the price. Its back and lay prices bracket the true price closely, which makes it a useful cross-check.
- Lay bet
- Betting that an outcome will not happen — taking the bookmaker's side on an exchange. A lay at L is equivalent to backing everything else at 1 + (1 − commission)/(L − 1), and it is staked as liability rather than as the amount entered.
- Closing line
- The final price before an event starts, after all money and information have arrived. The market's most informed estimate, and therefore the benchmark a bet's price is judged against.
For research, not betting advice. Positive expected value is an edge across many bets, never a prediction about one. Bet only what you can afford to lose. 18+.