Reference

Sports betting glossary

59 terms across 7 categories — plain English, no padding.

Wager types

Moneyline: Bet on who wins outright. Negative odds = favorite (risk $X to win $100); positive = underdog (win $X on $100 risked).
Point spread(Spread, Line, ATS): A handicap applied to level the sides. Favorite must win by more than the spread; underdog covers by losing by less (or winning).
Total(Over/Under, O/U): Bet whether combined score is over or under a number the book sets.
Parlay: Single bet combining multiple legs — all must win. Payouts compound; so does the vig.
Same-game parlay(SGP): Parlay within a single game. Books re-price for correlation, which typically increases hold.
Teaser: Multi-leg bet where you buy points on every leg (e.g. move NFL spreads 6 pts) in exchange for reduced odds.
Round robin: Group of smaller parlays from a larger set. A 3-team round robin → three 2-team parlays.
Prop bet(Proposition): Wager on something other than the final score — player stats, coin toss, first scoring play.
Futures: Long-term wager on a season or tournament outcome — championship, MVP, win totals.
Live bet(In-play): Wager placed after a game starts, with odds updating in real time.
Pleaser: Opposite of a teaser — you move the line against yourself in exchange for boosted odds.
If bet: Conditional sequence — next bet only places if the previous one wins.

American odds(US odds): Odds as +/− cents per $100. Negatives = favorites; positives = underdogs.
Decimal odds: Multiplier of stake including original wager. 2.50 decimal = +150 American.
Fractional odds: UK-style profit-to-stake. 5/2 = $5 profit on $2 risked.
Implied probability: Win probability encoded in the price. = 1 / decimal odds. -110 implies 52.38%.
Vig(Juice, Hold, Margin): Book's built-in margin. Sum implied probabilities of all outcomes — anything above 100% is the vig.
No-vig price(Fair odds): Price after removing the book's margin — best proxy for true probability.
+EV(Positive EV, Expected value): A bet whose long-run expected return is positive after vig. Found by comparing true probability to the book's implied probability.
-EV: A bet whose long-run expected return is negative. Every standard sportsbook bet at posted prices is -EV unless you've found an edge.
Closing line value(CLV): The difference between the price you got and the closing price. Consistent positive CLV is the single best long-term proxy for winning.
Sharp line: Pricing from professional books (Pinnacle, Circa, Bookmaker). Sharp lines are the most efficient.
Soft line: Pricing from a recreational book that hasn't caught up to consensus. Soft lines are where +EV is found.

Line movement: Change in posted odds over time — driven by action on one side or new information.
Steam move: Sharp, rapid movement at multiple books simultaneously — usually triggered by syndicate action.
Reverse line movement(RLM): Line moves opposite the public bets — e.g. 80% bet Team A but spread moves toward Team B. Strong sharp-money signal.
Sharp money: Bets from professional bettors and syndicates. Books move lines based on it.
Square money(Public money): Recreational bets — typically biased toward favorites, overs, and prime-time teams.
Opener: First line posted — often by a small number of sharp books before mass-market books copy.
Closer(Closing line): Final price before game time. The most efficient line of the cycle.
Limit: Maximum accepted on a single wager. Sharp books take high limits; recreational books take low ones.
Key number: A common margin of victory worth more than others. NFL: 3 and 7 dominate. NBA: smaller spikes at even numbers.

Push: Bet ties — stake is returned. No profit, no loss.
Cover: Winning a spread bet — favorite won by more than the spread, or underdog beat it.
Backdoor cover: Meaningless late score that flips the spread result. Classic bad beat.
Bad beat: Losing a bet in an unusually painful way — usually a garbage-time swing.
Void(No action): Bet is cancelled and refunded — player didn't start, game postponed, or rule condition unmet.

Bankroll: Total set aside for wagering — separate from bills, treated as risk capital.
Unit: Standard bet size, typically 1–2% of bankroll. Units let you communicate sizing independent of account size.
Kelly criterion: Bet-sizing formula: stake a fraction of bankroll proportional to your edge. Most bettors use quarter or half Kelly to control variance.
Hedge: Bet the opposite side of an existing position to reduce risk or lock in profit — usually at the cost of EV.
Arbitrage(Arb): Opposing bets at different books that guarantee profit regardless of outcome. Yields are usually 0.5–2%.
Middle: Two opposing lines create a window where both bets can win. E.g. +3.5 at Book A, -2.5 at Book B — favorite winning by exactly 3 cashes both.
Scalping: Trading small margins on opposing markets as lines move — similar to arbitrage but actively timed.
Devig: Removing the book's margin from a market to estimate true probabilities.
Line shopping: Comparing the same market across books to bet the best available price. Single most important long-term habit.
Bonus bet(Free bet): Promotional credit that returns only profit — not stake — if it wins. Worth roughly 60–80% of face value.
Promo abuse(Bonus bagging): Systematically converting promos to EV via hedging. Legal, but books may limit accounts.

Sharp: Long-term winning bettor — defined by sustained positive CLV more than short-term ROI.
Square: Recreational bettor — bets for fun, not profit. Books accept square action without limits.
Whale: High-volume recreational bettor. Books extend high limits and bonus offers.
Runner: Someone who places bets on behalf of a sharp who can't bet themselves (often limited or banned).
Beard: Person who uses someone else's identity to place bets — because the actual bettor is limited or banned.

Sportsbook: Licensed operator that accepts wagers. In the US, mobile sportsbooks are licensed at the state level.
Handle: Total wagered in a market or at a book over a period — not the same as revenue.
Hold percentage: Book's revenue as a % of handle. US books typically hold 7–9%.
GGR(Gross gaming revenue): Sportsbook winnings before promo deductions or operating costs.
Cashout: Settle an active wager early for less than the full payout. Almost always -EV.
Voided promo: Promotional credit revoked by a book when terms are violated or the book retroactively deems the bet ineligible.

See these concepts in action

The glossary is the map — the live tools are the territory. Find +EV bets and compare odds across every US sportsbook.