Sports Betting & Online Gambling Glossary
87 terms defined. An authoritative reference for Sports Betting & Online Gambling.
A
American Odds (Moneyline Odds)
An odds format used primarily in the US expressed as a positive or negative integer. Positive odds (e.g., +200) show profit on a $100 stake; negative odds (e.g., -150) show the stake needed to win $100.
Anytime Scorer
A wager on a player to score at any point during the game, regardless of timing or order. Anytime scorer bets offer lower odds than first or last goalscorer markets but are easier to land.
Arbitrage Betting (Arbing)
Placing opposing bets on all outcomes of an event across different bookmakers to guarantee a profit regardless of the result. Arbitrage requires significant capital and quick execution because discrepancies close fast.
Asian Handicap
A form of handicap betting that eliminates the draw outcome by giving a fractional or half-goal head start to the underdog. It reduces the bookmaker margin and provides two-outcome betting on traditionally three-outcome sports.
B
Back Bet
A standard wager that an outcome will occur, whether placed at a bookmaker or on an exchange. On an exchange, back bets are matched against lay bettors offering opposing positions.
Bankroll Management
The discipline of sizing bets as a percentage of your total gambling funds. Standard guidance: 1-5% per bet, never chase losses, and reduce size during losing streaks. The number one factor separating long-term winners from losers.
Best Odds Guaranteed (BOG)
A bookmaker promotion where the customer receives the higher of the odds taken at time of bet or the starting price at the off. BOG is common in UK horse racing and provides protection if prices drift.
Betting Exchange
A platform that matches opposing bettors directly rather than routing wagers through a traditional bookmaker. Users can back (bet for) and lay (bet against) outcomes, often finding better odds than standard books.
Bookmaker Margin
The percentage profit a bookmaker builds into a market by pricing outcomes at less than their true probability. Also called the vig or juice, the margin ensures the book profits regardless of the outcome.
Both Teams to Score (BTTS)
A market that pays out if both sides score at least one goal during the match. BTTS is independent of the final result and is often combined with match result markets in same-game parlays.
Buying Points
Paying a higher vig to move the point spread or total a half-point or full point in your favour. Buying points is most valuable when crossing key numbers, such as moving from -3 to -2.5 in football.
C
Closing Line
The final odds available immediately before an event begins. The closing line is considered the most efficient price because it reflects all available information and the full weight of sharp and public money.
Closing Line Value (CLV)
The difference between the odds when you place a bet and the final odds at game time. Consistently beating the closing line is the strongest indicator of long-term profitability. If you bet a team at +3.5 and it closes at +2.5, you got positive CLV.
Combination Bet
A wager that groups multiple selections into every possible accumulator of a given size. For example, a six-fold combination includes all possible doubles, trebles, and larger accumulators from six selections.
Cooling-Off Period
A temporary break from gambling, typically ranging from 24 hours to several months, that a bettor can set through their account. It prevents new deposits or bets during the selected period.
Correct Score Bet
A wager on the exact final scoreline of a match. Correct score markets offer high odds due to the difficulty of predicting the precise result, making them popular for accumulator combinations.
Cover
When a team wins by more than the point spread (favorites) or loses by less than the spread (underdogs). If the spread is -7 and the team wins by 10, they covered. Covering is what matters for spread bets, not just winning.
D
Decimal Odds
An odds format common in Europe and Australia where the number represents the total return per unit staked, including the stake itself. Odds of 2.50 mean a $10 bet returns $25 total ($15 profit).
Deposit Limit
A cap set by the bettor that restricts the maximum amount they can deposit into a gambling account over a daily, weekly, or monthly period. Deposit limits are an effective first-line tool for controlling spend.
Draw No Bet
A market where your stake is refunded if the game ends in a draw. It effectively removes the draw outcome, giving bettors a safety net while offering lower odds than a standard three-way market.
Drawdown
The peak-to-trough decline in a bettor's bankroll over a given period. Managing maximum drawdown is critical; even profitable bettors experience significant drawdowns due to variance.
Dutching
Distributing your stake across multiple selections in the same race or event so that each returns the same profit if it wins. Dutching increases hit rate at the cost of lower return per bet.
E
Early Market
Odds released well in advance of an event, often days or weeks ahead of the opening of the main market. Early markets typically carry lower limits as bookmakers have less information to price accurately.
Enhanced Odds
Enhanced odds are odds a bookmaker has deliberately raised above its own standard market price as a promotion — so a selection priced at 2.00 in the normal market might be offered at 4.00 to a qualifying customer. The uplift is marketing spend, not a mistake, and it is almost always fenced in by terms that decide whether the offer is worth taking. ## The terms that decide whether an enhanced-odds offer is actually good Read these five before you stake anything. They matter far more than the headline price: - **Maximum stake.** Enhanced prices are usually capped at a small qualifying stake. A price of 20.00 on a £/$10 cap is a very different offer from the same price uncapped. - **How the winnings are paid.** This is the single biggest variable. Some offers pay the enhanced portion in **cash**; many pay it in **free bets or bonus funds**, which are worth materially less. - **Whether the stake is returned.** With a free bet, you normally keep only the profit, not your stake back — so a "winning" free bet returns less than the same cash bet at the same price. - **Eligibility.** Many enhanced-odds offers are new-customer-only, or limited to one account, household or payment method. - **Wagering requirements.** Bonus funds may need to be turned over one or more times before they can be withdrawn. Cash winnings do not. ## Enhanced odds vs a price boost The two overlap and different books use the words differently, but in general use: - **Enhanced odds** tends to mean a large, heavily-conditioned promotional price — typically new-customer acquisition, capped stake, often paid in free bets. - A [price boost](/glossary/price-boost) tends to mean a smaller uplift offered to existing customers on a normal-sized stake, usually paid in cash. A boost with a modest uplift and cash settlement is frequently worth more in practice than a spectacular headline enhancement paid in bonus funds. ## A worked example (illustrative figures) Suppose the true market price is 2.00 and an offer enhances it to 5.00 with a 10-unit cap: - **Paid in cash, stake returned:** a win returns 50 units, of which 40 is profit. - **Paid as a free bet, stake not returned:** you receive 40 units of profit as bonus funds, and those funds must still be wagered before they become withdrawable. Same headline price, very different value. Work the settlement rules through before judging any offer. ## Is an enhanced price actually value? Convert it and compare. An enhanced price is only genuine value if it beats the selection's true chance of winning after the terms are applied — see [implied probability](/glossary/implied-probability), [fair value](/glossary/fair-value) and [expected value](/glossary/expected-value). A boosted price on an outcome that was badly overpriced to begin with can still be a losing bet, and the enhancement on a heavy favourite is often smaller in real terms than it looks. Also check whether [best odds guaranteed](/glossary/best-odds-guaranteed) applies, since promotional prices are commonly excluded from it. ## Responsible gambling Promotional pricing is designed to open accounts and increase stakes. Treat an enhanced price as a reason to bet only if you were already going to back that selection — never as a reason to find one. See [responsible gambling](/glossary/responsible-gambling) and [bankroll management](/glossary/bankroll-management).
Exchange vs. Sportsbook
A sportsbook sets its own odds and profits from the margin; a betting exchange matches bettors against each other and charges a commission on winnings. Exchanges often offer better prices but require more sophistication to use.
Expected Value (EV)
The average profit or loss per bet over the long run. Positive EV (+EV) means the bet is profitable over time. Calculated: (probability × payout) - (probability of loss × stake). Professional bettors only make +EV bets regardless of outcome on any single wager.
F
Fair Value
The price at which a bet is neither positive nor negative expected value, derived from an unbiased probability estimate. A bet priced above fair value represents a positive-EV opportunity.
First Goalscorer
A bet on which player will score the first goal of the match. Stakes are typically refunded if the selected player does not take part, and the market does not count own goals.
Flat Staking
A staking strategy where the same monetary amount is bet on every selection regardless of confidence level or odds. Flat staking is simple, eliminates stake-sizing errors, and makes record-keeping straightforward.
Fractional Kelly
A modified Kelly Criterion approach where a bettor wagers a fixed fraction (commonly half-Kelly) of the full Kelly stake recommendation. It reduces variance and drawdown risk while sacrificing some theoretical growth rate.
Fractional Odds
The traditional UK odds format displayed as a fraction (e.g., 5/2) representing profit relative to stake. The numerator is the profit and the denominator is the stake required to win that profit.
G
GambleAware
A UK charity and public health organisation that funds research, education, and treatment for gambling harms. GambleAware operates the National Gambling Helpline and the BeGambleAware campaign.
Game Props
Bets on specific in-game events that are not tied to the final result, such as the first team to score, total touchdowns, or race to 10 points. Game props add variety beyond standard spread and total markets.
H
Half-Time / Full-Time (HT/FT)
A market where you predict both the half-time result and the full-time result in a single bet. There are nine possible outcomes, creating attractive odds for punters who can assess momentum shifts.
Hong Kong Odds
An odds format that shows net profit per unit staked, similar to decimal odds minus 1. Odds of 1.50 in Hong Kong format mean a $10 bet returns $15 profit, for a total payout of $25.
I
Implied Probability
The probability of an outcome implied by the betting odds. Calculated: for -200 odds, it's 200/(200+100) = 66.7%. The gap between implied probability and your estimated true probability represents your potential edge.
In-Play Market (Live Betting)
Odds offered while an event is in progress, updating in real time as the action unfolds. In-play markets require fast decisions and carry risk of suspension if a key event occurs before a bet is confirmed.
Indonesian Odds
An odds format similar to American odds but expressed per unit staked rather than per $100. Positive Indonesian odds show profit per unit; negative values show the stake needed to win one unit.
K
Kelly Criterion
A mathematical formula for optimal bet sizing based on your estimated edge and odds. Formula: (bp - q) / b, where b = decimal odds - 1, p = win probability, q = loss probability. Most bettors use fractional Kelly (25-50%) to reduce variance.
Key Numbers
The most common margins of victory in a sport, particularly the NFL's 3 and 7. Lines that sit on or near key numbers carry extra significance because moving through them can substantially change win probability.
L
Lay Bet
A wager placed on a betting exchange where you act as the bookmaker, betting that a specific outcome will NOT happen. If the outcome you laid fails to occur, you collect the backer's stake minus commission.
Line Movement
Changes in odds or point spreads between opening and closing. Caused by betting volume, sharp action, injury news, or weather changes. Tracking line movement helps identify where smart money is going. Reverse line movement (line moves opposite to public betting) often signals sharp action.
Liquidity (Exchange)
The total amount of money available to be matched on a betting exchange market at a given price. Low liquidity means large bets may not be fully matched or may be filled at inferior prices.
Lucky 15
A 15-bet combination on four selections covering all singles, doubles, trebles, and the fourfold. Because singles are included, a Lucky 15 pays out if even one selection wins, often with a consolation bonus.
M
Malay Odds
An Asian odds format where positive values show profit per unit staked and negative values show the stake needed to win one unit. Malay odds range from -1 to +1 and are used widely in Southeast Asia.
Match Result & BTTS
A combined market requiring you to correctly predict both the match result and whether both teams will score. The combination increases odds while adding an extra layer of selection difficulty.
Matched Betting
A technique that uses free-bet promotions and betting exchanges to lock in a guaranteed profit. A qualifying bet at the bookmaker is hedged with a lay bet on the exchange, converting the free bet into cash.
Middle Opportunity
Arises when line movement creates a window where a bettor can win both sides of a wager. For example, betting +3 early and -2.5 later means a final margin of exactly 3 wins both bets.
Moneyline
A straight-up bet on which team or player will win, with no point spread. Favorites show negative odds (-200 = bet $200 to win $100), underdogs show positive odds (+150 = $100 bet wins $150). The simplest bet type available.
N
Negative EV
A bet where the mathematical expected return is less than the amount risked, meaning the bookmaker has an edge on that wager. Most recreational bets are negative EV due to the built-in margin.
No-Vig Odds
The true fair-value odds derived by removing the bookmaker's margin from a two-sided market. Comparing no-vig odds against posted odds helps bettors identify whether a line offers value.
O
Opening Line
The initial odds a bookmaker publishes for an event, before significant money has been wagered and before any line movement occurs. The opening line reflects the bookmaker's initial probability assessment.
Over/Under (Totals)
A bet on whether the combined score of both teams will be over or under a set number. Example: if the total is 47.5 and the final score is 28-24 (52), the over wins. Totals are influenced by weather, pace of play, and defensive matchups.
Overnight Line
Odds posted by a small number of bookmakers the evening before the game, typically with low betting limits. Overnight lines give sharp bettors early access and often move significantly by game time.
Overround
The bookmaker's built-in profit margin expressed as the percentage by which the sum of implied probabilities exceeds 100%. A market with an overround of 106% means the book is 6% in the bookmaker's favour.
P
Parlay
A single bet combining two or more selections — all must win for the bet to pay out. Offers higher payouts but exponentially lower probability. A 4-leg parlay at -110 each pays roughly 12:1 but wins only ~6.25% of the time. The sportsbook's most profitable bet type.
Patent Bet
A seven-bet combination covering three selections: three singles, three doubles, and one treble. A Patent returns a payout if just one selection wins, making it a safer but more expensive option than a Trixie.
Player Props
Wagers on individual player statistics or outcomes within a game, such as passing yards, points scored, or assists. Player props have expanded rapidly with data analytics and are popular in daily fantasy crossovers.
Point Spread
A handicap applied to the favorite to level the betting field. If a team is -7.5, they must win by 8+ points. The underdog at +7.5 covers if they lose by 7 or fewer (or win outright). Standard odds are -110 on both sides.
Positive EV Betting
The practice of only placing wagers where the expected value is greater than zero, meaning the long-run mathematical return is positive. Positive EV bettors use closing-line value as a proxy for identifying edges.
Pre-Game Market
Any betting market that closes before the event begins, as opposed to live or in-play betting. Pre-game markets include standard lines, totals, spreads, and most prop bets.
Price Boost
A promotional enhancement where a bookmaker temporarily increases the odds on a specific selection above their standard market price. Boosts are usually capped in stake and available for a limited time. A price boost is the smaller, cash-settled cousin of [enhanced odds](/glossary/enhanced-odds) — boosts are typically offered to existing customers on normal stakes, where enhanced-odds promotions tend to be larger, capped, new-customer-only and often paid in free bets rather than cash.
Problem Gambling
A gambling pattern that disrupts personal, family, or professional life, often characterised by chasing losses, lying about gambling, or inability to stop. It exists on a spectrum from at-risk behaviour to gambling disorder.
Profit and Loss (P&L) Record
A detailed log of all bets placed, including stakes, odds, outcomes, and running profit or loss. Maintaining a P&L record is essential for evaluating strategy performance and identifying areas for improvement.
Prop Bet (Proposition)
A bet on a specific event within a game rather than the final outcome. Player props: passing yards, touchdowns, rebounds. Game props: first team to score, coin toss result. Player prop markets are considered among the softest lines for skilled bettors to exploit.
Public Betting Percentage
The proportion of bets (by ticket count) placed on each side of a market, often published by sportsbooks. A high public percentage on one side can reveal square bias and potential reverse-line-movement opportunities.
R
Responsible Gambling
A set of practices and tools that help bettors gamble within their means and for entertainment rather than as a financial strategy. Responsible gambling includes setting limits, taking breaks, and seeking help if gambling becomes problematic.
Reverse Forecast
A bet predicting which two competitors will finish first and second in either order. Used mainly in horse racing and greyhounds, it covers both permutations and costs double a single forecast.
Reverse Line Movement
When a betting line moves in the direction opposite to the side receiving the majority of public bets. It signals that sharp money is backing the less-popular side in sufficient size to influence the line.
ROI in Sports Betting
Return on Investment expressed as net profit divided by total amount wagered, shown as a percentage. An ROI of 5% means you profit $5 for every $100 staked, which is considered excellent long-term performance.
S
Same-Game Parlay (SGP)
A parlay combining multiple bets from the same event. Sportsbooks price these with built-in correlation adjustments. Popular but the house edge is typically higher than separate bets. Savvy bettors look for positively correlated legs that the book underprices.
Self-Exclusion
A voluntary program that allows individuals to ban themselves from one or more gambling operators for a set period. Self-exclusion is a powerful harm-reduction tool available at most licensed bookmakers.
Sharp Money
Bets placed by professional or highly informed bettors that sportsbooks respect and react to. Sharp bets typically move lines. When 30% of bets but 70% of money is on one side, the money side is likely sharp. Sportsbooks limit or ban consistently sharp bettors.
Square Money
Wagers placed by recreational or public bettors who base decisions on team popularity, media hype, or emotion rather than statistical analysis. Square money tends to inflate lines on popular teams.
Staking Plan
A systematic method for determining how much to wager on each bet, such as flat staking, percentage of bankroll, or Kelly-based sizing. A disciplined staking plan protects capital during losing runs.
Standard Deviation (Betting)
A measure of the dispersion of betting results around the mean outcome. A higher standard deviation indicates wider swings in results, requiring a larger bankroll to withstand negative variance.
Steam Line
The consensus sharp line that emerges after heavy professional wagering moves the market. Tracking steam helps recreational bettors identify when sharps have identified value in a market.
Super Heinz
A 120-bet combination on seven selections covering all doubles, trebles, four-folds, five-folds, six-folds, and the sevenfold accumulator. It is one of the largest standard combination bets available.
T
Three-Way Market
A betting market that includes three possible outcomes: Home Win, Away Win, and Draw. Common in soccer, three-way markets require punters to account for the draw when assessing value.
Trixie Bet
A bet consisting of three selections combined into three doubles and one treble, totalling four bets. A Trixie returns profit if at least two selections win, reducing the all-or-nothing risk of a straight treble.
True Odds
The odds that would be offered if there were no bookmaker margin, perfectly reflecting the real probability of an outcome. Bettors seek posted odds that exceed true odds to find positive expected value.
Two-Way Market
A betting market with only two possible outcomes, such as a moneyline bet in a sport where draws are excluded. The bookmaker prices only Win or Loss, making the market simpler but often carrying a higher vig.
U
V
Value Betting
Identifying and wagering on outcomes where the bookmaker's odds imply a lower probability than your own model or assessment suggests. Sustained value betting is the foundation of long-term profitability.
Variance
The statistical measure of how widely actual results deviate from expected results over a sample of bets. High variance is normal in sports betting; it is why even skilled bettors experience losing streaks.
Vig (Vigorish/Juice)
The sportsbook's built-in commission on each bet. Standard vig is -110 on both sides of a spread — you bet $110 to win $100. The house keeps $10 regardless of outcome. Lower vig (-105) means better value. Shopping lines across books helps minimize vig paid.