121 betting terms in plain English, each linked to the lesson that teaches it.
Action — Money wagered. A book's action on a game is the total bet across all sides; a bet that has action is live and will be graded rather than voided.
Alternate line — A version of a spread or total set at a different number from the main one, with the price adjusted to match. Moving the number in your favour costs more juice; moving it against you pays more.
American odds — Prices written as a positive or negative number based on $100. A minus figure is what you must risk to win $100; a plus figure is what $100 wins. -110 and +150 are both American odds.
Arbitrage — Backing every outcome of the same event at different sportsbooks, at prices that guarantee a profit whichever way it goes. Real, but limited by stake caps, voided bets and lines that move before the second leg is placed.
Asian handicap — A soccer spread that removes the draw by giving one team a head start, sometimes in quarter-goals so that half the stake is refunded on a tie. Common on the leagues where a three-way market would otherwise carry a heavy fee.
Bad beat — A bet lost to something improbable and late — a meaningless score, an overtime field goal against a spread. Emotionally memorable and statistically meaningless, which is why it is a poor reason to change how you bet.
Balanced book — A market where equal money sits on both sides, so the sportsbook collects its fee regardless of the result. Textbooks describe it as the goal; in practice most books accept lopsided exposure when they believe their number is right.
Bankroll — The money set aside specifically for betting, separate from everything else you own. Bet sizes are set as a percentage of it, which is what stops a losing run from becoming a problem.
Beard — Someone who places bets on behalf of another person, usually because that person has been limited or banned. Against the terms of every sportsbook, and grounds for confiscating a balance.
Beat the close — To take a price better than the one the market finishes at. Doing it consistently is the earliest reliable sign that your process is sound, well before profit shows up.
Break-even — The win rate a price demands before you make any money. At -110 it is 52.38%, which is why betting coin flips at standard juice is a slow loss.
Buying points — Paying extra juice to move a spread or total in your favour, usually half a point at a time. Worth it only when the half point crosses a number games actually land on.
Cash out — A sportsbook offer to settle an open bet early for less than its full potential return. Convenient, and priced with a large fee — usually worse than hedging the same position yourself.
Chalk — The favourite. Betting chalk means backing the side the market expects to win, usually at a price that already reflects it.
Chasing — Increasing bet size to win back money already lost. It does not improve the odds of the next bet and is the most common route from a bad night to a serious problem.
Circled game — A market a sportsbook has restricted — lower limits, sometimes fewer bet types — usually because of an injury rumour, weather, or news the book has not fully priced yet.
Closing line — The final price a market offers before play begins. It has absorbed every injury, model and dollar of informed money, which makes it the market's best single estimate of the outcome.
Closing line value — The gap between the price you took and the closing line. Positive CLV means you got a better number than the market settled on, and it is the fastest honest evidence that a bettor is good.
Consensus line — A single price derived from many sportsbooks at once, usually after removing each one's fee. Used as a reference point for whether any individual book's price is generous or stingy.
Copycat book — A sportsbook that takes its numbers from the market rather than making its own. It moves after the originators move, which is why a slow copycat is where stale prices are found.
Correlation — When one leg of a parlay makes another more likely — a quarterback's passing yards and his team's total, for example. Books either forbid correlated combinations or reprice them, which is what a same-game parlay is.
Cover — To beat the point spread. A team favoured by 6.5 covers by winning by 7 or more; the underdog covers by losing by 6 or fewer, or winning outright.
De-vig — To strip a sportsbook's fee out of a set of prices and recover the probabilities underneath. The usual method divides each side's implied probability by their total.
Dead heat — A tie for a position in a market with several possible winners, most often in golf. Payouts are divided by the number of tied competitors, so a winning ticket can return less than its full price.
Decimal odds — Prices written as the total return per unit staked, stake included. 2.50 returns $2.50 for every $1 — a $1.50 profit. The standard almost everywhere outside the United States.
DFS — Daily fantasy sports: contests scored on real players' statistics over a single slate of games, rather than a full season. Legally distinct from sportsbook betting in many states.
Dime — Betting slang for $1,000. A nickel is $500 and a dollar is $100, which is why 'a dime on the under' is not a ten-cent bet.
Draw no bet — A soccer market where a draw refunds the stake instead of losing it. The price is shorter than the straight moneyline because the risk is lower.
Drawdown — The distance from a bankroll's peak to its lowest point afterwards. Every winning bettor has them; the size of the one you can survive is what sets your bet size.
Edge — How much better your estimate of an outcome is than the price you are being offered. A 2% edge means you think the bet wins two percentage points more often than the price implies.
Even money — A price that pays exactly what it risks, written +100 or 2.00. A true even-money market with no fee implies a 50% chance.
Exotic — Any bet outside the standard moneyline, spread and total — props, parlays, futures, novelty markets. Generally carries a higher fee than the main markets.
Expected value — What a bet is worth on average across many repetitions. Positive expected value means the price is better than your estimate of the true chance; it says nothing about whether this particular bet wins.
Exposure — The most a sportsbook — or a bettor — can lose on a given outcome. Books manage exposure by moving prices and cutting limits, not usually by refusing bets.
Fade — To bet against something — a team, a public trend, or a particular tipster. Fading the public is a popular idea that works far less often than it is repeated.
Fair odds — The price that matches the real probability of an outcome, with no sportsbook fee in it. Every value calculation compares an offered price against a fair one.
Favorite — The side the market expects to win. Marked by a minus sign on the moneyline and by giving points on the spread.
First-half line — A spread, total or moneyline covering only part of a game. Priced separately from the full-game line and usually carrying more juice.
Flat betting — Staking the same amount on every bet regardless of confidence. The simplest bankroll discipline there is, and the baseline any other staking plan has to beat.
Flex play — A pick'em entry that still pays something when one leg misses, at a lower multiplier than the all-or-nothing version. The reduced payout means it demands a different per-leg hit rate.
Fractional Kelly — Betting a fixed fraction of the Kelly stake — commonly a half or a quarter. Gives up a little growth for a large reduction in swings, and protects against overestimating your own edge.
Fractional odds — Prices written as a fraction of profit to stake. 3/2 pays $3 profit for every $2 risked. Standard in the UK and Ireland and still used for horse racing worldwide.
Free bet — A promotional bet that pays only the profit, not the stake. A $100 free bet at +200 returns $200, not $300 — which is why its cash value is well under its face value.
Futures — A bet on something decided at the end of a season — a championship, a division, an award. Prices are quoted for many competitors at once, and the combined fee is usually far larger than on a single game.
Grading — Settling a bet once the result is official. Delays usually mean a stat correction or an unofficial result, not a problem with the bet.
Handicapper — Someone who analyses games to predict results. Used both for people doing the work for themselves and for people selling picks, which are very different activities.
Handle — The total amount wagered on a market, a book or a whole state over a period. Distinct from revenue, which is the small slice of handle the books keep.
Hedge — Betting the opposite side of a position you already hold, to lock in a result rather than ride the outcome. It reduces expected value and buys certainty, which is sometimes exactly the right trade.
Hold — The share of every dollar wagered a sportsbook keeps once every side of a market is priced. A -110/-110 market holds about 4.55%; a futures market can hold 20% or more.
Hook — The half point on a spread or total. A team favoured by 7.5 is 'laying seven and the hook', and that half point exists to stop the bet pushing.
Implied probability — The chance a price corresponds to, before removing the sportsbook's fee. Because the fee is included, the implied probabilities of both sides of a market always add to more than 100%.
In-play — Prices offered while a game is being played, updated every few seconds as the situation changes. Carries a larger fee than pre-game markets and is usually subject to a betting delay.
Juice — The price attached to a spread or total — the -110 beside the number. Standard juice is -110 on each side; reduced juice books offer -105 or better and cost you less to bet through.
Kelly criterion — A formula for the bet size that grows a bankroll fastest given an edge. It is optimal only if your probability estimate is exactly right, so most people who use it bet a fraction of what it says.
Key number — A margin that games land on unusually often. In the NFL, 3 and 7 dominate because of how scoring works, which is why moving a spread across them costs much more than moving it elsewhere.
Laying points — Betting the favourite on the spread, and therefore giving the other side a head start. The opposite of taking points with the underdog.
Leg — One selection inside a multi-part bet. A three-leg parlay needs all three to win; a pick'em entry's legs are the individual player projections.
Limit — The largest bet a sportsbook will accept on a market. High limits signal a book's confidence in its number; low limits on a market usually mean it is not confident yet.
Limited — Having your maximum stake cut by a sportsbook, often to a few dollars, because it believes you are winning for reasons it does not like. Common at recreational books and rarely reversed.
Line movement — A change in a market's price between opening and closing. What moved it — news, informed money or public volume — matters far more than the fact that it moved.
Line shopping — Checking the same bet at several sportsbooks and taking the best available price. The most reliable edge available to anyone, because it requires no prediction at all.
Listed pitcher — A baseball bet condition requiring the named starters to actually start. If one is scratched the bet is normally voided rather than graded at the new price.
Live betting — Betting on a game already in progress. Prices update constantly, the fee is higher than pre-game, and a betting delay sits between your click and the acceptance.
Lock — Slang for a bet described as certain. No such bet exists — any market priced by a sportsbook has genuine uncertainty in it, and the word is most often used by someone selling picks.
Longshot — A selection at a long price, with a small chance of winning and a large payout. Longshots are systematically overbet, which is one of the oldest findings in betting research.
Low hold — Betting both sides of a market at two books where the combined fee is unusually small, so the guaranteed loss is close to zero. The near-miss version of an arbitrage.
Market efficiency — How completely a price reflects everything known about an event. Major-league closing lines are highly efficient, which is why beating them consistently is difficult and meaningful.
Market maker — A sportsbook that sets its own prices and accepts large bets to find the right number. Its line is the reference other books copy, and its closing number is the one worth measuring against.
Middle — Two bets on opposite sides at different numbers, where a result landing in the gap wins both. Backing +7 at one book and -5.5 at another middles on a six-point game.
Moneyline — A bet on who wins, with no spread involved. The favourite pays less than even money and the underdog pays more, which is how the market expresses the gap between them.
No action — A bet cancelled and refunded because a condition was not met — a postponement, a scratched pitcher, a game not going long enough to count.
No-vig line — A price with the sportsbook's fee removed, so the two sides add to exactly 100%. It is the market's honest estimate and the benchmark every value calculation uses.
Odds boost — A promotion raising the price on a specific bet above its normal number. Often the only genuinely positive-value offer a recreational sportsbook makes, subject to a stake cap.
Off the board — A market a sportsbook has pulled entirely, usually because of an injury it cannot price or news it cannot verify. It returns when the book is confident again.
Opening line — The first price a sportsbook posts on a market. Openers carry low limits precisely because the book expects to be corrected by the first informed bets.
Originator — A sportsbook that produces its own opening numbers rather than copying. There are only a handful, and the rest of the market follows them.
Over — The side of a total betting that the combined score, or a player's statistic, finishes above the posted number.
Overround — The sum of every outcome's implied probability in a market. It exceeds 100% in any normal market, and the excess is the sportsbook's fee.
Parlay — A single bet combining several selections, all of which must win. The payouts look large because the fee compounds with each leg, not because the book is being generous.
Payout — The total returned on a winning bet, stake included. A $100 bet at +150 pays out $250: the $100 back plus $150 profit.
Pick'em (DFS) — A fantasy contest where you choose more or less on a set of player projections and are paid a fixed multiplier for hitting a number of them. Not a sportsbook, and the payout tables are not odds.
Pick'em (spread) — A game with no favourite, where the spread is zero and the bet is simply on who wins. Written as PK on a board.
Player prop — A bet on an individual player's statistic rather than the game result — passing yards, points, strikeouts. Lower limits and a larger fee than game lines, and less thoroughly priced.
Point spread — A margin applied to the favourite to make both sides roughly equally likely. Betting a -6.5 favourite means it must win by 7 or more for the bet to win.
Power play — An all-or-nothing pick'em entry: every leg must hit, at a higher multiplier than the version that forgives a miss. Demands a much higher per-leg hit rate than it appears to.
Public money — Bets from recreational players, typically many small wagers concentrated on favourites, overs and popular teams. Books tolerate the imbalance because the money is not usually well-informed.
Puck line — Hockey's spread, almost always set at 1.5 goals because of how few are scored. The price does the work that a moving number does in other sports.
Push — A bet that lands exactly on the number and is refunded rather than won or lost. A -7 favourite winning by exactly 7 pushes.
Recreational book — A sportsbook built for casual customers: heavy promotion, low limits, parlays pushed hard, and quick restrictions on anyone who wins consistently.
Regression to the mean — The tendency of an extreme run of results to be followed by more ordinary ones. It explains most hot streaks without needing any story about form.
Reverse line movement — A line moving against the side most bets are on, which usually means a smaller number of larger, more respected wagers are on the other side.
ROI — Profit divided by total amount staked. Useful over thousands of bets and badly misleading over dozens, because a single longshot can dominate a small sample.
Rollover — A condition requiring a bonus to be wagered a number of times before it can be withdrawn. The multiple, and the minimum price each bet must be at, decide whether the bonus is worth anything.
Rotation number — The unique number beside each team on a betting board, used to identify a market unambiguously. Shared across the industry so the same game carries the same number everywhere.
Round robin — A set of smaller parlays automatically built from a list of selections, so not every pick has to win. It costs more in total stake and does not remove the compounding fee.
Run line — Baseball's spread, almost always 1.5 runs. Like the puck line, the number rarely moves and the price carries the adjustment.
Same-game parlay — A parlay whose legs all come from one game, repriced by the book to account for the ways the legs affect each other. That repricing is where most of its fee sits.
Sample size — How many bets a record covers. Betting outcomes are noisy enough that a few hundred bets tell you very little about whether someone is skilled.
Sharp — A bettor whose money sportsbooks respect enough to move their prices. Being sharp is defined by the market's reaction, not by a win-loss record.
Sharp book — A sportsbook that welcomes informed bettors, takes large limits and prices tightly, making money on volume and a small fee rather than on restricting winners.
Sharp money — Wagers from bettors a sportsbook takes seriously, usually few in number and large in size. It moves lines far more than the volume of public bets does.
Sportsbook — A business that prices betting markets and accepts wagers on them. VigWatch is not one — it compares prices and does not take bets.
Stake — The amount of money placed on a bet. American odds are quoted against a $100 stake, which is why -110 means risking $110 to win $100.
Stale line — A price a sportsbook has not yet updated after the rest of the market has moved. Genuinely valuable, briefly available, and the thing most positive-EV alerts are really finding.
Steam — A fast, coordinated line move across many sportsbooks at once, driven by respected money. By the time it is visible on a board, the price it was chasing has usually gone.
Straight bet — A bet on one outcome, with no other legs attached. The opposite of a parlay, and the format where the fee is smallest.
Sure bet — Another name for an arbitrage — a set of bets covering every outcome at prices that guarantee a profit. The name overstates how sure it is in practice.
Syndicate — A group betting together with shared models, capital and accounts. Syndicate money is what most references to sharp money are actually describing.
Team total — A total covering one team's score rather than the combined score. Useful when a view is about one side's offence rather than the pace of the whole game.
Teaser — A parlay where every spread or total is moved in your favour by a fixed number of points, at a reduced payout. Whether it is worth it depends almost entirely on which key numbers the move crosses.
Three-way market — A market with three outcomes rather than two, usually home, draw and away in soccer. Three sides means three prices to add up, and typically a larger combined fee.
Total — A market on the combined score of both teams. You bet whether the real number finishes above or below the one posted.
Tout — Someone who sells betting picks. Records are self-reported and rarely graded against closing lines, which is the check that would make them meaningful.
Under — The side of a total betting that the combined score, or a player's statistic, finishes below the posted number.
Underdog — The side the market expects to lose. Marked by a plus sign on the moneyline and by receiving points on the spread.
Unit — One standard bet, expressed as a fixed share of a bankroll — commonly 1%. Records are kept in units so that a result means the same thing whatever the bankroll behind it.
Value bet — A bet whose price is better than the true chance of it winning. The same idea as positive expected value, stated in words rather than arithmetic.
Variance — The natural swing in results around what the odds predict. It is why a bettor with a genuine edge can lose for months, and why short records prove very little.
Vig — The fee a sportsbook builds into its prices. It is charged on every bet, not only losing ones, and it is the main reason most bettors lose money over time.
Void — A bet cancelled and the stake returned. Voids are what turn a locked arbitrage into an unhedged position, because one leg can be voided while the other stands.
Yield — Profit as a percentage of total staked — the same calculation as ROI, and the term used more often outside the United States.