Glossary
Plain-English definitions of the core betting terms used across SmartStake — expected value, no-vig fair odds, hold, sharp books, devigging, and more.
How to use this glossary
These are the core terms that appear throughout SmartStake and the rest of these docs. Each definition is plain English; where a concept has its own page, that page goes deeper.
Terms
- Expected value (EV) — the average result of a bet if it could be placed an unlimited number of times. See Expected value & +EV betting.
- Positive EV (+EV) — a bet whose offered odds pay more than its true win probability warrants, making it profitable on average over a large sample even though any single bet can lose.
- No-vig fair odds — a book's price with the bookmaker's margin removed, so the implied probabilities sum to exactly 100%; SmartStake's estimate of the true, fair price. See No-vig fair odds & the hold.
- Hold — the percentage by which a market's implied probabilities exceed 100%; the book's built-in profit margin. Also called the vig or juice.
- Vig / juice — informal names for the hold, the margin a book builds into its odds to give it an edge whichever side wins.
- Devig — the act of removing the hold from a market to recover the no-vig fair odds. SmartStake offers five methods: power, multiplicative, additive, probit, and worst. See Devigging & fair value.
- Sharp book — a sportsbook whose odds reflect serious, well-informed money and so closely track true probability; SmartStake benchmarks fair value against a group of them. See Sharp books & why they're the benchmark.
- Line shopping — comparing the same bet across many books to take the best available price; a small price improvement on every bet compounds into a meaningful edge over time.
- Market width — how far apart the sharpest books are on the same market. A tight market gives a confident fair price; a wide market gives a noisier one and a less certain edge.
- Middle — a position where you back both sides of a market at different lines such that a result landing between them wins both bets, while any other result loses only the smaller margin.
- Arbitrage — backing the different outcomes of a market across books at prices that, in theory, return a profit on either side — though odds can move and bets can be limited or voided.
- Liquidity — how much money a market can absorb without its price moving; deep liquidity means large bets are accepted and prices tend to be more stable.
- Steam — a fast, sharp line move across many books at once, signalling that informed money has hit a side and the rest of the market is racing to catch up.
- Closing-line value (CLV) — the value of the price you got relative to the line at the moment the market closed. Beating the close consistently is a widely used educational signal that your prices were sharp. SmartStake measures this for your tracked bets and surfaces it across the Bet Tracker — see Closing line value.
For how the bankroll side of all this works, see Kelly criterion, bankroll & staking.
Important
- Odds, prices, expected value, conversion rates, and profit figures shown are estimates based on the last data we retrieved. They can change at any time — confirm the current price at the book before you bet, as odds may move and entry errors can occur.
- Arbitrage and matched betting carry execution risk: a price can move or a leg can be rejected before you place both sides, and sportsbooks may limit or void bets. A favorable outcome is not guaranteed.
- Using a “sharp” book as a fair-value reference is a modeling choice, not a statement of accuracy. Review a book’s record yourself and anchor on the books you trust.