Betting glossary: arbitrage and sports betting terms from A to Z

How to use this glossary

The terms are sorted A–Z. Each entry gives a short definition and, where it helps, a number you can check yourself. Where we have a full guide on the topic, the entry links to it. Local terms you will meet on Austrian, German and Slovak betting sites, such as AKO, Quotenschlüssel and Wettgebühr, are explained in English. Our betting basics guide puts the most important ones in order.

A

Accumulator (AKO)

One bet that combines several selections; all of them must win, and the odds are multiplied. Three selections at 1.50, 1.80 and 2.00 give combined odds of 5.40. In Austria and Germany it is often called an AKO or Kombiwette. Margins multiply too, which is why accumulators are rarely used for arbitrage.

Arbitrage betting (sure bet, arb)

Backing every outcome of an event at different bookmakers so that the payout is about the same whatever happens. It works when the best prices on all outcomes add up to less than 100% implied probability. The result depends on every leg being placed at the shown odds and standing. See sure betting explained.

Arb percentage

The size of a sure bet, usually quoted as the profit on the total stake: 1 / (1/odds₁ + 1/odds₂ …) − 1. At 2.10 and 2.05 the sum is 0.9640, so the arb is about 3.7%. Some tools quote 1 − sum (3.6%) instead. More in what is a good arbitrage percentage.

Asian handicap

A handicap market in quarter, half or whole goals that removes the draw. On whole lines a tie returns the stake (a push); quarter lines such as −0.25 split the stake over the two neighbouring lines, so a bet can be half won or half lost.

B

Back bet

An ordinary bet that something will happen, as placed at any bookmaker. The term is used mainly to contrast it with a lay bet on a betting exchange.

Bankroll

The money set aside only for betting, spread across your bookmaker accounts. Its size limits how large your stakes can be and how well you absorb voids, delays and variance. See our bankroll guide.

Betting exchange

A platform where users bet against each other instead of against a bookmaker; one side backs, the other lays. The exchange charges a commission on net winnings, typically 2–5%, which has to be priced into the odds.

C

Closing line

The last odds available before an event starts. Because they include all information up to kick-off, closing odds at sharp bookmakers are regarded as the best estimate of the true probability.

Closing line value (CLV)

How much better your odds were than the closing odds. Taking 2.10 on a selection that closes at 1.95 is 2.10 / 1.95 − 1 ≈ 7.7% CLV. Consistently positive CLV is the usual evidence of value betting. See closing line value.

D

Decimal odds

The odds format used in Austria, Germany and Slovakia: the total payout per unit staked, stake included. €10 at 2.50 returns €25, a profit of €15.

Devig (margin-free odds)

Removing the bookmaker's margin from a set of odds to estimate fair probabilities. At 1.90 / 1.90 the implied probabilities add up to 105.3%; scaled back to 100% each side is 50%, fair odds 2.00. See no-vig fair odds.

Draw no bet (DNB)

A football market where you back a team and get your stake back if the match is drawn. It equals an Asian handicap of 0. Backing one team draw no bet at one bookmaker and the other team draw no bet at another is a two-way market like tennis.

Dutching

Splitting one stake over several selections in the same event so that each returns the same amount. With €70 on two runners at 3.00 and 4.00, stakes of €40 and €30 both return €120. See the dutching calculator.

E

Edge

The advantage of a bet over its fair price, as a percentage. A sure bet's edge is its arb percentage; a value bet's edge is its expected value.

Expected value (EV)

The average result per unit staked if a bet could be repeated many times: odds × probability − 1. At odds 2.10 and a fair probability of 50%, EV = 2.10 × 0.5 − 1 = +5%. Single results can still be losses. See expected value betting.

F

Free bet (SNR / SR)

A bet placed with bookmaker credit instead of your own money. With a stake-not-returned (SNR) free bet you keep only the winnings; with stake returned (SR) you also get the stake back, which makes it worth more. Example: a €10 SNR free bet at 4.00, covered with €22.06 at 1.36 elsewhere, returns about €7.94 either way, a retention of about 79%, if both bets stand. See free bets.

G

Gubbing

British slang for an account that has been excluded from promotions: no more free bets, boosts or bonuses, while normal betting may continue. It is one form of the restrictions described in bookmaker limits.

H

Hold

The share of the money staked that a bookmaker keeps on a market in the long run. For a balanced market it is close to 1 − 1/overround: at 1.90 / 1.90 the hold is about 5%.

I

Implied probability

The probability a price suggests: 1 / decimal odds. Odds of 2.50 imply 40%. Because of the margin, the implied probabilities of all outcomes add up to more than 100%. See implied probability.

J

Juice (vig, vigorish)

American terms for the bookmaker's margin, the same thing as overround. "Reduced juice" books offer tighter prices, such as 1.95 / 1.95 instead of 1.90 / 1.90.

K

Kelly criterion

A formula for staking on positive expected value: stake share = (b × p − q) / b, where b is the odds minus 1, p the win probability and q = 1 − p. At 2.10 and p = 50%, Kelly suggests (1.10 × 0.5 − 0.5) / 1.10 ≈ 4.5% of the bankroll; most bettors use a fraction of that. See the Kelly criterion.

L

Lay bet

A bet that something will not happen, offered on a betting exchange: you act as the bookmaker for another user's back bet. Laying is how matched bettors cover a back bet at a bookmaker.

Liability

What you stand to lose on a lay bet: lay stake × (odds − 1). Laying €50 at 3.00 means a liability of €100 if the selection wins; if it loses you win the €50 stake, minus commission.

Limit (account restriction)

A cap a bookmaker places on how much a specific customer may stake, sometimes down to a few euros. Bookmakers limit customers who win consistently, and it is the main practical constraint on arbitrage. See bookmaker limits.

Line shopping

Comparing prices at several bookmakers and placing each bet where the odds are best. Over hundreds of bets, small price differences add up. See line shopping.

M

Margin

The bookmaker's built-in edge in a market: the sum of 1/odds for all outcomes minus 1. At 1.90 / 1.90 the margin is 5.3%. See bookmaker margin and overround.

Matched betting

Using bookmaker promotions, mainly free bets, and covering each bet with a lay bet or an opposite bet so that the promotion's value is locked in. It depends on promotions being available, which ends once an account is gubbed.

Middle

Two bets on different lines of the same market where both can win if the result lands in between. Over 2.5 goals at one bookmaker and under 3.5 at another both win with exactly three goals; otherwise one leg wins and the other loses, usually for a small loss. See middles.

Mug bet

Slang for a bet placed for its own sake rather than for an edge, typically a popular market at an ordinary price. Some advantage bettors place them so their accounts look recreational. They cost expected value and don't prevent limits.

O

Overround

The total of the implied probabilities in a market, such as 105.3% at 1.90 / 1.90. Anything above 100% is the margin; a sum below 100% across bookmakers is a sure bet.

P

Palp (palpable error)

A price so obviously wrong that the bookmaker's terms allow it to void the bet or resettle it at the correct odds. Unusually large arbs are often palps. See voided bets and palpable errors.

Push

A result where the bet is neither won nor lost and the stake is returned, for example a draw on draw no bet, or exactly two goals on a handicap or total of 2.0.

Q

Qualifying bet

The bet with your own money that a bookmaker requires before it releases a bonus or free bet. Its minimum odds and stake are set in the promotion's terms.

Quotenschlüssel (payout percentage)

German term for the share of stakes a market pays back: 1 / overround. At 1.90 / 1.90 it is 1 / 1.0526 = 95%. The higher the Quotenschlüssel, the lower the margin.

R

Rollover (wagering requirement)

How many times a bonus (or bonus plus deposit) must be staked before it can be withdrawn. A €50 bonus with a 5× rollover requires €250 of bets, often at minimum odds.

S

Sharp bookmaker

A bookmaker that takes large stakes at low margins and moves its prices on informed money rather than limiting winners. Its odds are the usual reference for fair prices. See sharp vs soft bookmakers.

Soft bookmaker

A bookmaker aimed at recreational customers, with higher margins, bonuses and slower price updates. Most sure bets and value bets are found at soft bookmakers, and they are also the ones that limit winning accounts.

Stake factoring

A per-customer multiplier on a bookmaker's standard maximum stake. A factor of 0.1 means you may stake only 10% of the normal limit. It is the internal mechanism behind most account limits.

Steam

A sharp, quick price movement across many bookmakers, usually after informed money or news. Bookmakers slow to follow steam briefly offer prices that create sure bets or value bets.

V

Value bet

A bet whose odds are higher than the fair odds, so its expected value is positive. Unlike a sure bet it can lose; the edge only shows over many bets. Value bets in ArbVantage are coming soon. See value betting.

Void

A bet cancelled by the bookmaker and settled as if it had not been placed, with the stake returned. Common causes are palpable errors, a postponed event or a retirement under some rules. A voided leg turns a sure bet into a single open bet.

W

Wettgebühr (Austrian betting fee)

The Austrian fee on sports bets, 5% of the stake since April 2025. The bookmaker owes it, but some pass it on: if 5% is deducted from the stake, displayed odds of 2.00 effectively become 1.90. See the Austrian betting tax.

Y

Yield

Profit divided by total amount staked (turnover). €150 profit on €10,000 of bets is a 1.5% yield. It is the standard way to compare betting results of different sizes.

FAQ

What does sure bet mean?

A sure bet (also called an arb) is a set of bets on every outcome of an event, placed at different bookmakers, whose best prices add up to less than 100% implied probability. If every leg is placed at the shown odds and stands, the payout is about the same whatever the result. It is a small margin, not a guarantee.

What is a push?

A push is a result where your bet is neither won nor lost and the stake is returned, for example a draw on a draw-no-bet bet, or exactly two goals on a total of 2.0.

What does gubbing mean?

Gubbing is British slang for an account that a bookmaker has excluded from promotions. You can usually still bet, but you no longer receive free bets, boosts or bonuses.

What is the Quotenschlüssel?

Quotenschlüssel is the German term for a market's payout percentage: 1 divided by the sum of 1/odds. At odds of 1.90 on both sides it is 95%, meaning the bookmaker keeps about 5% of the stakes in the long run.

Sources

• RIS: Gebührengesetz 1957, § 33 TP 17 (Austrian betting fee)
• Úrad pre reguláciu hazardných hier (ÚRHH): licences and prohibited offers, Slovakia
• Kelly, J. L. (1956): A New Interpretation of Information Rate, Bell System Technical Journal
• Kaunitz, Zhong, Kreiner (2017): Beating the bookies with their own numbers, arXiv:1710.02824

As of October 2026. Examples use decimal odds and are illustrations, not betting, legal or tax advice. 18+.

Betting involves risk, sure bets included: odds move, bets get voided and accounts get limited. Only stake money you can afford to lose. If betting stops being fun, our responsible gambling page lists free help in Austria and Germany.