A gambling glossary in plain English. 77 betting terms, casino terms and poker terms, from acca to Yankee, each with a quick example and a link to a free calculator so you can try the numbers yourself. If a word on a betting slip or a casino offer has you stuck, it’s probably here.
Gambling glossary A to Z
A B C D E F G H I K L M N O P R S T V W Y
A
- Acca insurance
- An offer that refunds your stake, usually as a free bet, if one leg of an acca loses. Worth less than it looks, because a free bet isn’t cash. See the acca insurance calculator.
- Accumulator (acca)
- One bet on several selections, where every leg has to win. The odds multiply, so four picks at 2.0 pay 16.0. Try the acca calculator.
- American odds
- Odds written as +150 or −120. Plus shows the profit on a 100 stake, minus shows what you stake to win 100. +150 is 2.50 in decimal. The American to decimal calculator converts them.
- Ante post
- A bet placed well before the day, often weeks ahead of a big race, usually at bigger odds. The catch: if your horse doesn’t run, you normally lose the stake. See ante post betting.
- Any to come (ATC)
- A bet where some of the return from one bet funds the next, only if the first one wins. Common in UK betting shops as “single stakes about”. See the any to come calculator.
- Arbitrage (arb)
- Backing every outcome at different bookmakers so you profit whatever happens. Rare, small, and accounts that do it get limited fast. The arbitrage calculator splits the stakes.
- Asian handicap
- A football handicap that removes the draw, often with half or quarter goals. −0.5 is the same as backing a team to win. See the Asian handicap calculator.
B
- Banker
- In baccarat, one of the two main bets, and the best one: about a 1.06% house edge with 5% commission. Also a betting slang word for a “sure thing”, which doesn’t exist.
- Bankroll
- Money set aside only for gambling, separate from bills and savings. Bet sizes are planned as a share of it. The betting bankroll calculator helps you size bets.
- Basic strategy
- The best play for every blackjack hand against every dealer card. Following it cuts the house edge to roughly 0.5%. See the blackjack strategy chart.
- Bet builder
- Several selections from the same match on one slip. The legs are linked, so the price isn’t simply the odds multiplied. See the bet builder calculator.
- Both teams to score (BTTS)
- A football bet on both sides scoring at least once. The BTTS calculator works out a fair price from expected goals.
- Bust
- In blackjack, going over 21, which loses at once. A dealer showing a 6 busts about 42% of the time. See the blackjack bust calculator.
C
- Cash out
- Settling a bet early for an amount the bookmaker offers. It always carries a margin, so it costs a little on average. The cash out calculator shows the fair figure.
- Closing line value (CLV)
- How your price compares with the odds just before the start. Beating the closing line regularly is the best sign you’re betting well. See the CLV calculator.
- Correct score
- A bet on the exact final score. Long odds and high margins. The correct score calculator builds a full score grid.
D
- Dead heat
- A tie for a place in a race. Your stake is split by the number of runners tied, so a two-way dead heat pays half. See the dead heat calculator.
- Decimal odds
- Odds that include the stake. 3.00 returns £3 for every £1, so £2 profit. The easiest format for sums. The odds converter handles every format.
- Double chance
- A football bet covering two of the three results, like home or draw. See the double chance calculator.
- Draw no bet
- A bet on a team to win where your stake comes back if it’s a draw. See the draw no bet calculator.
- Dutching
- Backing several selections in one market with stakes set so every winner pays the same. See the dutching calculator.
E
- Each way
- Two bets in one: a win bet and a place bet at a fraction of the odds. £5 each way costs £10. The each way calculator works out the returns.
- Edge
- The average share of each bet you win or lose over time. A player edge is positive, a house edge is negative for you.
- Exchange
- A betting site where you bet against other people, not a bookmaker. You can back or lay, and the site takes a commission on winnings.
- Expected value (EV)
- What a bet is worth on average if you could make it thousands of times. A £10 bet with −5% EV costs 50p on average. See the EV calculator.
F
- Fractional odds
- UK-style odds such as 5/2, the profit for each unit staked. 5/2 means £5 profit for every £2. The fractional to decimal calculator converts them.
- Free bet
- A stake from the bookmaker. If it wins you usually get the profit only, not the stake back, so a £10 free bet at evens pays £10. See the free bet calculator.
G
- Gambler’s fallacy
- Believing a result is “due” because it hasn’t happened lately. Roulette has no memory. The gambler’s fallacy simulator shows why.
H
- Half-time/full-time
- A football bet on the result at half-time and at full-time, nine combinations in all. See the HT/FT calculator.
- Hedging
- Placing a bet against your original one to lock in a profit or cut a loss. See the hedge calculator.
- Hit frequency
- How often a slot pays anything, including wins smaller than your stake. See the slot hit frequency calculator.
- House edge
- The casino’s average cut of every bet. European roulette is 2.70%, so £100 staked loses £2.70 on average. See the house edge calculator.
I
- ICM
- The Independent Chip Model, which turns tournament chips into prize money. Chips aren’t worth their face value near the money. See the ICM calculator.
- Implied odds
- In poker, pot odds plus what you expect to win later in the hand if you hit. See the implied odds calculator.
- Implied probability
- The chance a price suggests. 4.0 decimal implies 25%. Add up a whole market and it comes to more than 100%, which is the bookmaker’s margin. See the implied probability calculator.
K
- Kelly criterion
- A formula that sizes bets by your edge and the odds. Full Kelly swings wildly, so most people use half or a quarter. See the Kelly calculator.
L
- Lay bet
- Betting that something won’t happen, on an exchange. You take the bookmaker’s side and your liability can be bigger than the stake. See the lay calculator.
- Liability
- What you stand to lose on a lay bet. Laying £10 at 5.0 risks £40.
- Lucky 15
- Fifteen bets on four selections: four singles, six doubles, four trebles and a fourfold. See the Lucky 15 calculator.
M
- Margin (overround)
- The bookmaker’s built-in profit. If a market’s implied probabilities add up to 105%, the margin is about 4.8%. See the margin calculator.
- Martingale
- Doubling your stake after every loss. Each win clears the losses, until a long streak hits the table limit or your bankroll. See the martingale calculator.
- Matched betting
- Using a free bet offer and laying the same selection on an exchange, so you profit whatever happens. See the matched betting calculator.
- mBTC
- A millibitcoin, one thousandth of a bitcoin. Common as a crypto casino stake unit. The crypto stake converter shows it in pounds.
- Megaways
- A slot reel layout where the number of symbols on each reel changes every spin, so the ways to win change too, up to 117,649. See how Megaways slots work.
- Middle
- Two bets on either side of a line, at different numbers, so a result in between wins both. See the middle calculator.
- Minimum defence frequency (MDF)
- In poker, how often you need to continue against a bet so a bluff with any two cards doesn’t profit. See the MDF calculator.
- Moneyline
- A bet on who wins, quoted in American odds. Common in Canada for hockey and basketball. See the moneyline calculator.
N
- Nap
- A tipster’s best bet of the day. If a paper lists six tips, the nap is the one they’d put their own money on.
- No-vig odds
- A bookmaker’s prices with the margin taken out, so the probabilities add up to 100%. See the no-vig calculator.
- NRNB (non-runner no bet)
- An ante post concession: if your selection doesn’t run, the stake comes back instead of being lost.
O
- Outs
- In poker, the cards left in the deck that improve your hand. A flush draw on the flop has nine. See the rule of 2 and 4 calculator.
P
- Parlay
- The North American name for an accumulator. See the parlay calculator.
- Patent
- Seven bets on three selections: three singles, three doubles and a treble. See the patent calculator.
- Penetration
- How deep into the shoe a dealer goes before shuffling. Deeper means counting cards is worth more.
- Place terms
- How many places an each way bet pays and at what fraction, such as 1/5 odds for the first four. The extra place calculator covers offers with more places.
- Poisson distribution
- A model of how many goals a team scores from its expected goals. It underpins most football price calculators. See the Poisson calculator.
- Pot odds
- The pot size against the cost of calling. Calling £10 into a £30 pot needs to win 25% of the time. See the pot odds calculator.
- Profit boost
- An offer that increases your winnings by a percentage, usually with a cap. See the profit boost calculator.
- Provably fair
- A system crypto casinos use so you can check each result from a server seed, client seed and nonce after the bet. See the provably fair calculator.
R
- Rakeback
- A share of the rake (poker) or of your staking (casino) paid back to you. See the casino rakeback calculator.
- Return to player (RTP)
- The share of all stakes a game pays back over the long run. 96% RTP means a 4% house edge. Your own sessions will rarely match it.
- Risk of ruin
- The chance of losing your whole bankroll before you reach a goal or stop. See the risk of ruin calculator.
- ROI (return on investment)
- Profit as a share of total stakes. £150 profit from £3,000 staked is 5% ROI. See the betting ROI calculator.
- Rule 4
- A deduction from horse racing winnings when a runner is withdrawn after you bet. See the Rule 4 calculator.
S
- Sats (satoshis)
- The smallest unit of bitcoin, one hundred-millionth of a coin. 100,000 sats is 1 mBTC.
- Scorecast
- A bet on the first goalscorer and the correct score together. See the scorecast calculator.
- SP (starting price)
- The official odds when a race starts. Take SP and you’re paid at that price whatever it was when you bet. See starting price explained.
- Stake
- The amount you bet. Not to be confused with your return, which includes the stake.
- Starting price (SP)
- The odds at the moment a race starts. Your bet is settled at SP if you didn’t take a price.
- Sticky bonus
- A casino bonus that can’t be withdrawn, only played with. See the sticky bonus calculator.
T
- True count
- In blackjack card counting, the running count divided by the decks left. It’s what drives bet size. See the card counting calculator.
V
- Variance
- How far results swing around the average. High-variance bets give long losing runs and the odd big win. See the betting variance calculator.
- Vig (vigorish)
- The bookmaker’s margin, the name used in North America. See the vig calculator.
- Volatility
- How a slot spreads its RTP: frequent small wins (low) or rare big ones (high). Same average, very different sessions.
- VPIP
- Voluntarily put money in pot: the share of hands where a poker player calls or raises before the flop. Around 20 to 25% is typical for a solid six-max player. See the VPIP calculator.
W
- Wagering requirement
- How many times you must play through a bonus before you can withdraw it. A £50 bonus at 35× needs £1,750 of bets. See the wagering calculator.
Y
- Yankee
- Eleven bets on four selections: six doubles, four trebles and a fourfold, with no singles. See the Yankee calculator.
Missing a term? Use the contact form and we’ll add it. For how the numbers on this site are worked out, see how we calculate.