Mega Glossary
322 gambling terms, defined
Professional definitions for the language of betting, odds, math, poker, casino games, racing, regulation, and responsible play.
Showing 322 of 322 terms.
A
Action
Any wager placed, or the activity of betting itself. 'Live action' refers to wagers placed while a game is in progress.
American Odds
Odds format that shows the profit on a $100 wager (positive) or the stake needed to win $100 (negative).
Arbitrage
Wagering on all outcomes of an event at different sportsbooks such that a profit is guaranteed regardless of result.
Arb
Shorthand for arbitrage.
Against the Spread
Wagering on a team to cover the point spread rather than win outright. Abbreviated ATS.
ATS
Against the spread; a team's record relative to the point spread.
Alternate Line
A non-standard point spread or total with adjusted odds offered alongside the main line.
Asian Handicap
A spread format common in soccer that eliminates the draw outcome by using quarter-point increments.
Anchoring Bias
Over-relying on the first piece of information encountered when making subsequent judgments.
Availability Heuristic
Estimating likelihood based on how easily examples come to mind rather than actual base rates.
All-In
Wagering one's entire stack on a single hand.
Ante
A forced bet contributed by all players before a hand begins.
Across the Board
Equal wagers on a horse to win, place, and show.
Allowance Race
A race where horses run for higher purses without being for sale, governed by weight allowances based on past performance.
AGA
American Gaming Association: the trade group representing the US gaming industry.
Age Verification
The required process by which operators confirm a customer is of legal gambling age.
AML
Anti-money laundering: regulatory frameworks operators must follow to detect and report suspicious activity.
B
Bankroll
The total amount of money dedicated specifically to gambling, kept separate from personal finances.
Bet
A wager of money on a defined outcome with agreed-upon terms.
Bettor
A person who places wagers.
Book
Short for sportsbook: the operator or venue accepting wagers.
Bookmaker
An entity that sets odds, accepts wagers, and pays winners. Also called a bookie.
Buy-In
The amount required to enter a game, tournament, or pool.
Best Price
The most favorable available odds for a given selection across sportsbooks.
Bayes Theorem
A mathematical rule for updating probability estimates as new information becomes available.
Beard
A person who places wagers on behalf of someone else, often to circumvent limits.
Bonus
A promotional credit offered by a sportsbook, typically with wagering requirements.
Buy Points
Paying additional juice to move a spread or total in your favor by a half-point or more.
Bankroll Management
The discipline of allocating, sizing, and protecting capital dedicated to gambling.
Bet Sizing
Determining how much to wager based on edge, variance, and bankroll.
Behavioral Economics
A field combining psychology and economics to explain how real people deviate from rational decision-making.
Blind
A forced bet posted by one or two players before cards are dealt.
Bluff
Betting or raising with a weak hand to make opponents fold stronger holdings.
Board
The community cards dealt face up in games like Hold'em and Omaha.
Button
The dealer position, which acts last on each post-flop street and is the most advantageous seat.
Bankroll Requirement
The capital needed to weather expected variance for a chosen game and stake.
Basic Strategy
The mathematically optimal play for every blackjack situation against the dealer's upcard.
Backstretch
The straight portion of the track opposite the grandstand; also the stable area.
Box
A wager covering all combinations of selected horses in an exotic bet.
C
Cash Out
Settling an open wager early for a price offered by the sportsbook before the event concludes.
Chalk
The favorite, often a heavy favorite. 'Betting chalk' means backing favorites.
Closing Line
The final odds offered by a sportsbook immediately before a market closes.
Cover
To beat the point spread. A favorite must win by more than the spread; an underdog must lose by less or win outright.
Closing Line Value
The difference between the price you secured and the closing price; a leading indicator of long-term edge.
CLV
Shorthand for closing line value.
Conditional Probability
The probability of an event occurring given that another event has already occurred.
Confidence Interval
A range of values within which a true parameter is expected to fall with a specified probability.
Circled Game
A game with reduced betting limits due to uncertainty such as injuries or weather.
Consensus
The percentage of bettors or money on each side of a market.
Cover
Beating the point spread.
Capping
Slang for handicapping; analyzing a game to set a personal projection.
Correlated Parlay
A parlay whose legs are statistically related, such as a team to win and the over.
Chasing Losses
Increasing bet sizes after losses in an attempt to recover, typically a destructive behavior.
Cognitive Bias
A systematic deviation from rationality in judgment.
Confirmation Bias
Seeking, interpreting, and remembering information in ways that confirm pre-existing beliefs.
Confidence Bias
Overrating the accuracy of one's own judgments and predictions.
Calling Station
A player who calls too frequently and rarely raises or folds.
Check-Raise
Checking with the intent to raise after an opponent bets.
Continuation Bet
A bet on the flop by the preflop raiser, regardless of whether the flop helped their hand.
Card Counting
Tracking the ratio of high to low cards remaining in a blackjack shoe to identify favorable conditions.
Comp
A complimentary good or service awarded to a player based on their tracked play.
Comps Rate
The percentage of expected loss returned to a player as complimentary benefits.
Croupier
A dealer at a table game such as roulette or baccarat.
Claiming Race
A race in which every entered horse may be purchased for a stated price.
Compact
A negotiated agreement between a state and a federally recognized tribe governing gaming on tribal lands.
D
Dog
Short for underdog: the team or side expected to lose.
Decimal Odds
Odds format showing total return per unit staked, including the original stake. 2.00 means even money.
Devigging
The process of removing the vig from posted odds to estimate true market probabilities.
Dependent Events
Events where the outcome of one affects the probability of another, such as card draws without replacement.
Dime
Slang for a $1,000 wager.
Dime Line
A baseball moneyline market where the price gap between favorite and underdog is 10 cents.
Dog Player
A bettor who systematically backs underdogs.
Dollar
Slang for a $100 wager.
Double Action
An if-bet that pays a follow-up bet whether the first wins or pushes.
Drawdown
The peak-to-trough decline of a bankroll over a losing stretch.
Decision Fatigue
Deterioration in decision quality after extended periods of decision-making.
Disposition Effect
The tendency to hold losing positions too long while closing winners too early.
Drawing Dead
Holding a hand that cannot win regardless of future cards.
Daily Double
A wager requiring the bettor to pick the winners of two consecutive races.
Dead Heat
Two or more horses finishing exactly tied for a placing.
Daily Fantasy Sports
Short-duration fantasy contests in which entrants select rosters under a salary cap.
DFS
Abbreviation for daily fantasy sports.
E
Edge
A statistical advantage a bettor or operator holds over the other party.
Expected Value
The average outcome of a wager if repeated infinitely, calculated as (win probability x payout) - (loss probability x stake).
EV
Shorthand for expected value.
Expected Loss
The average amount a bettor or player expects to lose per wager given a negative expected value.
Equity
A player's mathematical share of the pot based on their probability of winning the hand.
Early Money
Wagers placed soon after a market opens, often by sharp professionals.
Even Money
A bet that pays out exactly the amount wagered, expressed as +100 in American odds.
Exotic
A wager more complex than a straight bet, such as parlays, teasers, and props.
Edge Percentage
The percent advantage a bettor estimates over the no-vig line.
Expected Growth
The projected long-run rate at which a bankroll grows given consistent edge and sizing.
Endowment Effect
Valuing something more highly simply because you own it.
Equity
A hand's mathematical share of the pot based on its win probability.
Even Money
A blackjack option to take a 1:1 payout on a player blackjack when the dealer shows an ace.
Eye in the Sky
Surveillance cameras monitoring casino floor activity.
Exacta
A wager requiring the bettor to pick the first two finishers in exact order.
F
Favorite
The team or outcome expected to win, indicated by a minus sign in American odds.
Field
All entrants in a contest, or a wager covering all unlisted competitors.
Fixed Odds
Odds locked in at the moment a wager is placed regardless of subsequent line movement.
Fractional Odds
Odds expressed as a ratio of profit to stake, common in UK markets. 5/1 means $5 profit per $1 wagered.
Fractional Kelly
Sizing wagers at a fraction (typically 1/4 to 1/2) of full Kelly to reduce volatility and modeling risk.
Flat Betting
Wagering the same amount on every play regardless of perceived edge.
First Half Bet
A wager on the outcome of only the first half of a game.
Futures
Wagers on long-term outcomes such as championship winners or season totals.
Framing Effect
Reaching different conclusions based solely on how the same information is presented.
Float
Calling a bet with a weak hand intending to bluff a later street.
Fold Equity
The portion of a bet's expected value that comes from the chance an opponent folds.
Face Card
A jack, queen, or king in a standard 52-card deck.
Furlong
One-eighth of a mile, the standard unit of race distance.
G
Grading
The process by which a sportsbook settles a wager as won, lost, pushed, or void.
Game Selection
The discipline of only betting markets where you have a defensible edge.
Gambler's Fallacy
Belief that past independent outcomes affect the probability of future ones, such as expecting heads after several tails.
GTO
Game theory optimal: a strategy that cannot be exploited regardless of opponent adjustments.
Game Prop
A prop wager on game-level outcomes such as first scoring play or total touchdowns.
GPP
Guaranteed prize pool: a tournament-format DFS contest with a fixed payout pool.
Geofencing
Location verification technology that restricts online wagering to users physically present within legal jurisdictions.
H
Handle
Total dollar amount wagered on a market, event, or by an operator over a period.
Hold
The percentage of total handle a sportsbook keeps as gross gaming revenue.
House
The casino or sportsbook accepting wagers.
House Edge
The mathematical advantage a casino game holds over the player over the long run, expressed as a percentage of the wager.
Hong Kong Odds
Odds format that expresses profit per unit staked. 1.50 means $1.50 profit on a $1 wager.
Half Time Bet
A wager placed after halftime on the outcome of the second half.
Handicapper
A person who analyzes events and recommends wagers.
Hedge
Placing a wager opposite an existing position to reduce risk or lock in profit.
Home-Field Advantage
The statistical edge teams enjoy playing on their home field, often built into power ratings.
Hook
The half-point on a spread or total, important because games rarely land exactly on key whole numbers.
Hindsight Bias
The tendency to perceive past events as more predictable than they were at the time.
Hot Hand Fallacy
Belief that streaks predict future independent outcomes when they often do not.
Hand Range
The full set of hands a player could plausibly hold given their actions.
Heads-Up
A pot or game involving only two players.
Hard Hand
A blackjack hand with no ace, or with an ace counted as 1.
High Roller
A player who wagers large amounts and typically receives premium comps.
Hit
In blackjack, requesting another card.
Hold Percentage
The percentage of buy-in or handle a casino retains as revenue.
Handicap Race
A race in which weights are assigned to horses to equalize their chances of winning.
Handle
Same as General entry: total amount wagered.
I
Implied Probability
The probability of an outcome inferred from posted odds, after stripping out the sportsbook's margin.
Independent Events
Events whose outcomes do not influence one another, such as successive roulette spins.
If Bet
A sequential wager where the second bet is only placed if the first wins, pushes, or sometimes loses.
In-Game Betting
Wagering on events while a game is in progress, with odds updating in real time.
Information Edge
An advantage derived from data, analysis, or sources unavailable to most of the market.
Illusion of Control
Overestimating one's ability to influence events that are largely or wholly chance-based.
Implied Odds
Expected future winnings on later streets if a draw completes, beyond the current pot odds.
Insurance
A side bet in blackjack against the dealer having a natural 21 when showing an ace.
IGRA
Indian Gaming Regulatory Act of 1988: the federal law that governs tribal gaming in the US.
J
K
L
Limit
The maximum amount a sportsbook will accept on a given wager.
Line
The current odds, spread, or total a sportsbook is offering.
Lock
Slang for a wager presented as a sure thing. Real locks do not exist in legitimate markets.
Long Shot
A bet with a very low implied probability and a correspondingly high payout.
Law of Large Numbers
The principle that as the number of trials grows, observed results approach expected values.
Line Movement
Changes in a sportsbook's odds between opening and closing, driven by money and information.
Line Shopping
Comparing odds across sportsbooks before placing a wager to secure the best price.
Limit Bet
A wager placed at the maximum amount the sportsbook will accept.
Live Betting
Same as in-game betting.
Lookahead Line
Odds posted well in advance of an event, often less efficient than later lines.
Long-Term Thinking
Evaluating decisions by their expected value over many repetitions rather than single-outcome results.
Loss Limit
A pre-set maximum loss for a session or period after which betting stops.
Loss Aversion
Losses feel psychologically about twice as painful as equivalent gains feel pleasurable.
Limp
Entering a pot by calling the big blind rather than raising.
Licensed Operator
A sportsbook or casino authorized by a regulator to accept wagers in a jurisdiction.
M
Market
A specific betting offering, such as a moneyline, total, or prop.
Moneyline
A wager on which team wins outright with no point spread.
Market-Implied Probability
The probability the aggregate market assigns to an outcome, derived from sharp closing lines.
Margin
A sportsbook's built-in profit, expressed as the excess of implied probabilities above 100%.
Market Efficiency
The degree to which posted prices accurately reflect all available information about an outcome.
Middling
Wagering both sides of a spread or total at different numbers, creating a window where both can win.
Monte Carlo Simulation
A computational technique using repeated random sampling to estimate the distribution of possible outcomes.
Money Management
Disciplined practices for sizing bets and managing bankroll.
Model
A quantitative system used to project outcomes and identify mispriced markets.
Modeled Probability
A win probability output by a bettor's projection system used to compare against market prices.
Mental Accounting
Treating money differently based on its source or intended use rather than its fungible value.
Made Hand
A hand that has value as-is, not relying on improvement.
Muck
To fold; also the pile of discarded cards.
Marker
A short-term credit line extended by a casino to qualified players.
Maiden Race
A race restricted to horses that have never won a race.
Morning Line
The track handicapper's early prediction of likely final odds before public betting begins.
Mutuel Pool
The total amount wagered into a pari-mutuel pool from which winners are paid after the track's takeout.
N
No-Vig Probability
Implied probability adjusted to remove the sportsbook's vigorish for a true probability estimate.
Normal Distribution
A symmetric, bell-shaped probability distribution that describes many natural phenomena and large-sample statistical results.
Nickel
Slang for a $500 wager.
Nuts
The best possible hand at a given moment given the board.
O
Off the Board
A game or market temporarily removed from wagering, often due to injury news or uncertainty.
Opening Line
The first odds released for a market before betting action moves the price.
Odds
A ratio expressing the relative likelihood of an outcome occurring versus not occurring.
Overround
The amount by which a market's implied probabilities sum above 100%, representing the operator's margin.
Off the Board
Same as the General entry: a market temporarily not accepting wagers.
Outright
Winning the event itself, not just covering a spread or finishing in a placed position.
Over
A wager that the combined score will exceed the posted total.
Outcome Bias
Judging the quality of a decision by its result rather than by the information available at the time.
Overconfidence
Estimating one's skill or knowledge as greater than it actually is.
Outs
The number of remaining cards that improve a hand to a winner.
Overbet
A bet larger than the size of the pot.
Ownership
The percentage of DFS entries that include a given player.
Offshore Sportsbook
A sportsbook operating from outside the United States, generally unlicensed and unregulated in any US jurisdiction.
P
Parlay
A single wager combining two or more selections; all must win for the parlay to win.
Payout
The total amount returned to the bettor on a winning wager, including stake and profit.
Point Spread
A handicap assigned by oddsmakers to balance betting action between two sides.
Prop
A wager on something other than the final result, such as player statistics or game events.
Push
A tie between the bettor and the sportsbook; the stake is refunded.
Positive EV
A wager whose expected return exceeds its cost. The cornerstone of profitable betting.
Probability
A number between 0 and 1 representing the likelihood of an event occurring.
Public Money
Wagers from recreational bettors, often skewed toward favorites and overs.
Pot Odds
In poker, the ratio of the current pot size to the cost of a contemplated call.
Poisson Distribution
A probability distribution used to model the number of independent events occurring in a fixed interval, common in soccer score modeling.
P-Value
The probability of observing results at least as extreme as the actual results assuming the null hypothesis is true.
Power Rating
A numerical estimate of a team's strength, often used to project point spreads and totals.
Pick'em
A game with no spread because both sides are viewed as equal.
PK
Abbreviation for pick'em.
Pleaser
The opposite of a teaser: a multi-leg wager that moves spreads against the bettor in exchange for higher payouts.
Player Prop
A prop bet on an individual player's statistical performance.
Power Ranking
A ranking of teams based on quality of performance, often used as a basis for spread projections.
Price
The odds attached to a particular outcome.
Prop Bet
A wager on a specific occurrence or non-occurrence within an event.
Puck Line
The NHL spread, typically set at 1.5 goals.
Process Over Outcome
Evaluating decisions by the quality of reasoning at the time rather than by the result.
Pattern Recognition Bias
Seeing meaningful patterns in random data.
Probability Misjudgment
Systematic errors in estimating likelihoods, often overweighting rare events and underweighting common ones.
Prospect Theory
Kahneman and Tversky's framework describing how people evaluate gains and losses asymmetrically.
Position
A player's seat relative to the dealer button; later position confers strategic advantage.
Pit
An area of the casino floor containing table games supervised by pit bosses.
Player Tracking
Systems that record a player's wagers to calculate theoretical loss and award comps.
Progressive Jackpot
A jackpot that grows with each wager until it is won.
Push
A tie between player and dealer in blackjack; the wager is returned.
Pari-Mutuel
A betting system in which winners share the pool after the operator takes its commission, rather than betting against the house.
Pick Six
A wager requiring the bettor to select the winners of six designated races.
Place
A bet that a horse will finish first or second.
Pick'em Game
A simplified DFS-style product where users select players over or under projected stat lines.
PASPA
Professional and Amateur Sports Protection Act of 1992, struck down by the US Supreme Court in 2018.
Problem Gambling Hotline
A confidential helpline staffed to support individuals affected by gambling harm.
Q
R
ROI
Return on investment: profit divided by total amount risked, expressed as a percentage.
Regression to the Mean
The tendency for extreme observations to be followed by values closer to the long-run average.
Reverse Line Movement
When the line moves opposite to the side receiving most of the public bets, suggesting sharp action on the other side.
Risk of Ruin
The probability that a bankroll will be depleted given a strategy's edge, variance, and bet sizing.
Round Robin
A collection of smaller parlays generated from a group of selected wagers.
Run Line
The MLB spread, typically set at 1.5 runs.
Recency Bias
Overweighting the most recent information when forming judgments.
Range Advantage
Holding a stronger overall set of possible hands than your opponent on a given board.
Rake
The commission charged by a cardroom on each pot or tournament entry.
Rake
Same as Poker entry: the commission charged by the cardroom.
Return to Player
The long-run percentage of wagers a game returns to players, the complement of house edge.
RTP
Abbreviation for return to player.
Responsible Gambling
Practices and tools designed to keep gambling a controlled and informed activity.
S
Sharp
A professional or highly skilled bettor whose action sportsbooks respect.
Spread
Short for point spread, the handicap applied to even the betting on two sides.
Square
A recreational bettor whose action typically follows public sentiment rather than analysis.
Stake
The amount of money risked on a wager.
Sportsbook
A licensed operator that accepts wagers on sporting events.
Standard Deviation
The square root of variance; a common measure of how spread out outcomes are around the mean.
Sample Size
The number of trials or observations. Larger samples are needed to distinguish skill from luck.
Steam Move
Sharp, sudden line movement across the market, often triggered by professional money.
Sharp Money
Wagers from respected professional bettors that books watch closely and often follow.
Soft Line
A posted price that is materially off from a sharp consensus, creating a potential edge.
Stale Line
A price that has not updated to reflect new information, briefly creating an arbitrage or value opportunity.
Scalping
Betting both sides of a market at different prices to lock in a small guaranteed profit.
Same Game Parlay
A parlay combining multiple correlated selections from a single event.
SGP
Abbreviation for same game parlay.
Sides
Betting on which team will win, either outright or against the spread.
Soccer Three-Way
A soccer moneyline market with three outcomes: home win, away win, or draw.
Square Play
A wager typical of recreational bettors, often on favorites or overs.
Steam
Sudden, sharp line movement across the market driven by professional action.
Straight Bet
A single wager on one outcome with no additional conditions.
Sample Bias
A distortion in conclusions caused by data that does not represent the underlying population.
Selection Bias
Bias introduced when the data sampled is not representative of the target population.
Session Bankroll
The portion of total bankroll allocated for a specific session or day.
Stop Loss
A predetermined threshold at which a bettor stops wagering to preserve bankroll.
Sunk Cost Fallacy
Continuing a course of action because of previously invested resources rather than future expected value.
Semi-Bluff
Betting or raising with a hand that has both fold equity and equity to improve if called.
Set
Three of a kind using a pocket pair and one matching board card.
Showdown
The point at the end of a hand when remaining players reveal cards to determine a winner.
Stack
The total chips a player has at the table.
Shoe
The dealing device that holds multiple decks of cards.
Side Bet
An optional secondary wager available on many table games, typically with higher house edge.
Slot
A reel-based gaming machine with randomized outcomes determined by an RNG.
Soft Hand
A blackjack hand with an ace counted as 11.
Surrender
A blackjack option to forfeit half the wager rather than play out the hand.
Show
A bet that a horse will finish in the top three.
Stakes Race
A high-quality race with entry fees that contribute to a substantial purse.
Superfecta
A wager requiring the bettor to pick the first four finishers in exact order.
Salary Cap
A spending limit DFS entrants must observe when selecting their roster.
Stacking
A DFS strategy of pairing correlated players, such as a quarterback and wide receiver from the same team.
Self-Exclusion
A voluntary program allowing individuals to ban themselves from gambling establishments or accounts for a defined period.
State Regulator
The government agency responsible for licensing and overseeing gambling activity within a state.
T
Total
A wager on whether the combined score of both teams will be over or under a posted number. Also called the over/under.
True Odds
The actual probability of an outcome, distinct from the posted odds that include vigorish.
Teaser
A multi-leg wager allowing the bettor to adjust spreads or totals in their favor at reduced odds.
Three-Way Line
A moneyline with three possible outcomes, common in soccer and hockey regulation markets.
Total Bet
Wagering on the combined score relative to a posted number; the over/under.
Tracking
Recording every wager with relevant context to evaluate process and results over time.
Tilt
An emotional state, often triggered by losses, in which judgment deteriorates and risk-taking increases.
Three-Bet
The first re-raise preflop.
Table Game
A casino game played at a table with a dealer, such as blackjack, baccarat, or roulette.
Theoretical Loss
A player's expected loss based on house edge and total wagered, used for comp calculations.
Takeout
The percentage withheld from each pari-mutuel pool by the track and state.
Trifecta
A wager requiring the bettor to pick the first three finishers in exact order.
Tribal Gaming
Gaming operated by federally recognized tribes under IGRA and compacts with states.
U
Underdog
The team or side expected to lose, indicated by a plus sign in American odds.
Unit
A standardized bet size used to track performance independent of bankroll size, typically 1-5% of bankroll.
Under
A wager that the combined score will be less than the posted total.
Unit Size
A standardized wager amount, typically 1-5% of bankroll.
UIGEA
Unlawful Internet Gambling Enforcement Act of 2006: a US federal law restricting payment processing for unlawful internet gambling.
V
Vig
Short for vigorish: the sportsbook's commission embedded in the odds.
Vigorish
The fee a sportsbook charges for placing a bet, mathematically built into the odds.
Variance
The statistical dispersion of outcomes around the expected value. High variance means more swings.
Value Bet
A wager where the estimated true probability exceeds the implied probability of the offered odds.
Variance Tolerance
The psychological ability to remain disciplined through normal statistical swings.
Variance
The natural short-term swings between expected and actual results.
Volatility
How frequently and dramatically a game's outcomes deviate from its expected return.
W
Wager
A formal bet on a specified outcome.
Win Rate
The percentage of wagers won out of total wagers placed.
Wong Teaser
A football teaser strategy that crosses through key numbers like 3 and 7.
Whale
An extremely high-stakes player whose action significantly affects casino revenue.
Win
A wager that a horse will finish first.
Wire Act
The 1961 federal law restricting interstate transmission of wagering information, primarily applied to sports betting.