This glossary defines 80+ sportsbook and sports betting terms — organized alphabetically for quick lookup. Whether you are a prediction market trader expanding into sports betting, a developer building AI sports betting agents, or someone new to the industry, this is your reference.

If you are coming from the prediction market side, you will notice that many sportsbook concepts have direct equivalents in the prediction market world. We call those out throughout. For the companion glossary covering prediction market and agent-specific terminology, see the Agent Betting Glossary or the Prediction Market Terminology guide.

Use your browser’s search (Ctrl+F / Cmd+F) to jump to a specific term.

A

Accumulator

A bet that combines multiple selections into a single wager where all selections must win for the bet to pay out. The odds compound multiplicatively — a three-leg accumulator at +100, +100, and +100 pays 7-to-1 rather than 2-to-1 three separate times. Accumulators are the European term for what Americans call a parlay. Prediction market equivalent: there is no native equivalent, but some traders manually construct correlated multi-market positions.

Account Longevity

The length of time a bettor can maintain an active sportsbook account before being limited or banned. Sharp bettors and bot operators often measure success partly by account longevity. Offshore sportsbooks generally offer longer account longevity than regulated US books for winning players. For developers building AI sports betting agents, account longevity is a critical operational metric alongside ROI.

Action

A general term meaning a live wager. “Having action” on a game means you have money at stake on the outcome. The term also describes the total dollar amount wagered on an event — “the action on the Super Bowl was $200 million.” Prediction market equivalent: open position or exposure.

Against the Spread (ATS)

A team’s record relative to the point spread, as opposed to their straight win-loss record. A team can be 10-6 straight up but 5-11 ATS if they frequently win by fewer points than the spread requires. ATS records are a core data point for handicappers and agent models evaluating spread bets.

American Odds

The odds format standard in the United States. Expressed as positive or negative numbers relative to $100. Positive odds (+150) indicate profit on a $100 wager — +150 means you win $150 on a $100 bet. Negative odds (-150) indicate the amount you must wager to win $100. To convert to implied probability: positive = 100 / (odds + 100); negative = |odds| / (|odds| + 100). See also: decimal odds, fractional odds, implied probability.

Asian Handicap

A spread betting format originating in Asian markets that eliminates the possibility of a draw by using half-point and quarter-point spreads. A team at -0.75 means half the stake is on -0.5 and the other half on -1.0. Asian handicaps are especially common in soccer betting. They allow more granular pricing than standard spreads and reduce the probability of a push.

Arbitrage (Arb)

Placing bets on all outcomes of an event across different sportsbooks such that a guaranteed profit is locked in regardless of the result. An arb exists when the combined implied probability of the best available odds across books totals less than 100%. Typical arb margins range from 1-3%. Prediction market equivalent: cross-platform arbitrage between exchanges like Polymarket and Kalshi. See: Sports Betting Arbitrage Bot Guide.

B

Bad Beat

A bet that appears to be a sure winner but loses due to an unlikely late event — such as a last-second touchdown that flips the spread result. Bad beats are statistically inevitable over large sample sizes and are irrelevant to long-term expected value analysis, but they feature prominently in bettor psychology.

Bankroll

The total amount of money a bettor has allocated specifically for wagering. Professional bettors and agent operators manage bankroll separately from personal finances. Bankroll management — typically using Kelly criterion or fractional Kelly — determines bet sizing as a percentage of total bankroll. Prediction market equivalent: trading capital or portfolio allocation.

Bonus

A promotional incentive offered by sportsbooks to attract new customers or retain existing ones. Common types include deposit match bonuses (100% match up to $1,000), free bets, and odds boosts. Bonuses typically come with rollover requirements. Prediction market equivalent: deposit incentives or fee rebates (less common).

Bot Detection

Systems sportsbooks use to identify automated betting activity. Detection methods include analyzing bet timing patterns, session behavior, browser fingerprinting, CAPTCHA challenges, and velocity checks on wager placement. Sportsbooks that detect bots typically ban accounts immediately. Developers building sports betting automation must account for bot detection in their architecture. See: AI Sports Betting Agents.

Bought Half Point

The practice of paying additional vig to move a spread by half a point in your favor. Buying the hook on a -3 spread moves it to -2.5, crossing a key number. The cost varies by sportsbook and by how significant the number is — buying off of 3 or 7 in football is more expensive because those are the most common margins of victory.

C

Chalk

Slang for the favorite in a matchup. “Playing the chalk” means betting on favorites. The term originates from horse racing, where odds were written in chalk on boards and favorites were updated most frequently.

Circled Game

A game on which the sportsbook has reduced the maximum bet size, often due to uncertainty about player injuries, weather, or other information. Circled games signal the book’s own risk management concerns. They are useful signals for agent models — a circled game often indicates that important information is in flux.

Closing Line

The final odds offered by a sportsbook just before an event starts. The closing line is considered the most efficient price in sports betting because it incorporates all available information and market activity. See also: closing line value, opening line.

Closing Line Value (CLV)

A measure of whether a bettor consistently obtains odds better than the closing line. If you bet a team at -3 (-110) and the line closes at -3.5 (-110), you captured positive CLV. Beating the closing line is the single most reliable predictor of long-term profitability in sports betting. CLV tracking is a primary evaluation metric for AI sports betting agents. Prediction market equivalent: the alpha of getting filled at better prices than the final settlement probability. See: Sharp Betting strategies.

Consensus

The most common line offered across the sportsbook market. If 15 out of 20 sportsbooks have a spread at -7, the consensus line is -7. Deviation from consensus often indicates sharp action or proprietary modeling at the books that differ. Consensus data is available through odds aggregation APIs.

Contrarian Betting

A strategy that deliberately bets against the public majority. The theory is that public money creates inflated lines on popular teams, and the sportsbooks shade lines to exploit recreational bias. Contrarian strategies work best when combined with sharp-side indicators rather than blindly fading the public. Prediction market equivalent: trading against sentiment-driven positions.

Cover

When a team wins by enough points to beat the spread. If the spread is -7 and the team wins by 10, they covered. If they win by exactly 7, it is a push.

D

Decimal Odds

An odds format common in Europe and Australia. Represents the total return on a $1 bet including the original stake. Decimal odds of 2.50 mean a $1 bet returns $2.50 ($1.50 profit + $1.00 stake). To convert to implied probability: 1 / decimal odds. To convert from American: positive = (odds / 100) + 1; negative = (100 / |odds|) + 1. See also: American odds, fractional odds.

Deposit

Transferring funds into a sportsbook account. Regulated US sportsbooks accept bank transfers, credit cards, PayPal, and Venmo. Offshore sportsbooks commonly use cryptocurrency (Bitcoin, USDT, Ethereum), person-to-person transfers, and bank wires. Deposit methods affect both speed and fees. Prediction market equivalent: funding a wallet or exchange account.

Dog (Underdog)

The team or side expected to lose, carrying positive American odds. A +200 underdog means a $100 bet returns $200 profit. Opposite of favorite or chalk.

Dime Line

A moneyline where the difference between the favorite and underdog prices is 10 cents (e.g., -120/+110). Dime lines represent low vig and are favorable for bettors. Some sharp-friendly offshore sportsbooks offer dime lines on popular markets. A “20-cent line” (-130/+110) is more typical at standard books.

E

Edge

The advantage a bettor has over the sportsbook’s line. If your model estimates a team’s win probability at 55% but the implied probability from the odds is 50%, your edge is 5 percentage points. Positive expected value (+EV) betting is built on identifying and exploiting edges. Prediction market equivalent: alpha or informational edge over the market price.

Expected Value (EV)

The average profit or loss per bet over the long run. Calculated as: (probability of winning x profit) - (probability of losing x stake). A bet with positive expected value (+EV) is profitable over time regardless of any single outcome. All professional sports betting and agent strategies are built on identifying +EV opportunities. Prediction market equivalent: expected return on a position.

Exotic Bet

Any bet type beyond standard moneyline, spread, or totals. Exotics include parlays, teasers, round robins, and complex prop bets. Exotics typically carry higher vig than straight bets. Sportsbooks earn a disproportionate share of revenue from exotic wagers.

F

Favorite

The team or side expected to win, carrying negative American odds. A -150 favorite requires a $150 wager to win $100. The opposite of dog (underdog). Prediction market equivalent: the outcome priced above 50 cents.

First Half / Second Half Bet

A wager on the result of only the first or second half of a game, independent of the final score. Half bets offer a separate spread, moneyline, and total. They represent discrete sub-markets and are commonly used by sharp bettors who model half performance separately.

Fixed Odds

Odds that are locked in at the time of the bet and do not change regardless of subsequent line movement. All standard sportsbook bets in the US are fixed odds — you get the price displayed when you place the wager. Contrast with pari-mutuel systems (horse racing) or prediction market continuous trading, where the price fluctuates until settlement.

Fractional Odds

An odds format traditional in the UK. Expressed as a fraction (5/1, 3/2, 11/10). The numerator is the profit and the denominator is the stake. Fractional odds of 5/1 mean a $1 bet returns $5 profit plus your $1 stake. To convert to implied probability: denominator / (numerator + denominator). See also: American odds, decimal odds.

Futures

A bet on an outcome that will be decided in the future, typically weeks or months away. Examples include betting on a team to win the championship before the season starts, or a player to win MVP. Futures odds move continuously throughout the season as probabilities shift. Prediction market equivalent: a long-duration contract like “Will the Lakers win the 2027 NBA Championship?”

G

Grading

The process by which a sportsbook settles a bet as a win, loss, or push after the event concludes. Automated grading systems resolve most standard bets within minutes. Prop bets and exotic wagers may require manual grading and can take longer. Grading disputes are more common at offshore sportsbooks than at regulated ones. Prediction market equivalent: resolution.

H

Halftime Line

Odds posted during halftime of a game for the second half only. Halftime lines incorporate first-half performance data and are considered sharper than pre-game lines because they reflect updated information. Modeling halftime lines is an advanced use case for AI betting agents.

Handle

The total dollar amount wagered on a specific event or across a sportsbook over a given period. “The Super Bowl handle was $180 million at Nevada sportsbooks.” Handle is distinct from hold — handle is the total wagered, hold is the sportsbook’s profit. Prediction market equivalent: total volume.

Handicapper

A person who analyzes sporting events and predicts outcomes, often selling their picks to others. Professional handicappers use statistical models, film study, and insider knowledge. The term also refers to the sportsbook employee who sets opening lines. In the AI betting context, an agent’s model layer serves the handicapping function. See also: tout.

Hedge

Placing a second bet on the opposite side of an existing wager to reduce risk or guarantee profit. Common with futures bets — if you bet a team at +2000 to win the championship and they reach the finals, you can hedge by betting the opponent to lock in profit regardless of the final outcome. Prediction market equivalent: selling a position or taking the opposing side.

Hold

The percentage of total handle that a sportsbook retains as profit. Hold is the actual realized margin, as opposed to the theoretical overround. If $1,000,000 is wagered and the book keeps $50,000 after paying winners, the hold is 5%. Industry average hold on NFL sides is 5-7%. Prediction market equivalent: platform revenue as a percentage of trading volume.

Hook

Half a point in a spread. “Getting the hook” means having a half-point advantage — for example, getting +3.5 instead of +3. In football, the hook on key numbers like 3 and 7 is extremely valuable because those are the most common margins of victory.

I

Implied Probability

The probability of an outcome as derived from betting odds. For American odds: positive = 100 / (odds + 100); negative = |odds| / (|odds| + 100). For example, -150 implies a 60% win probability; +200 implies a 33.3% win probability. Because vig is baked into both sides, the sum of implied probabilities always exceeds 100% at a single book. Removing the vig yields the no-vig line or true implied probability. Prediction market equivalent: the contract price, which directly represents probability. See: Odds Converter.

In-Play Betting (Live Betting)

Wagering on an event while it is in progress. Odds update continuously based on the current score, time remaining, and game flow. In-play markets have wider spreads and lower limits than pre-game markets due to the speed of information change. In-play betting is the fastest-growing segment of sports wagering and a major target for real-time agent systems. Prediction market equivalent: trading active contracts where the underlying event is unfolding in real time.

J

Juice

Another term for vig (vigorish). The commission built into the odds that ensures the sportsbook profits. Standard juice is -110 on both sides of a spread, meaning each side must risk $110 to win $100. “Reduced juice” books offer -105 or -108, lowering the bettor’s cost. Prediction market equivalent: maker/taker fees on an exchange. See also: vig, overround.

K

Kelly Criterion

A mathematical formula for calculating the optimal bet size given your estimated edge and the offered odds. The Kelly formula is: f = (bp - q) / b, where f is the fraction of bankroll to wager, b is the decimal odds minus 1, p is the estimated win probability, and q is 1 - p. Most professionals use fractional Kelly (quarter or half) to reduce variance. The Kelly criterion applies identically to prediction market position sizing.

Key Numbers

Point spread values that correspond to the most common margins of victory in a sport. In NFL football, 3 and 7 are the primary key numbers because field goals (3 points) and touchdowns with extra points (7 points) are the most common scoring plays. Games landing on key numbers account for a disproportionate share of results, making the hook around these numbers especially valuable.

KYC (Know Your Customer)

Identity verification required by regulated sportsbooks before allowing deposits or withdrawals. KYC typically requires government ID, proof of address, and sometimes a selfie. Regulated US sportsbooks enforce strict KYC. Offshore sportsbooks vary widely — some require minimal verification, others none at all for crypto deposits. Prediction market equivalent: Kalshi requires full KYC; Polymarket requires varying levels depending on jurisdiction and activity level.

L

Laying Points

Betting on the favorite and accepting the point spread disadvantage. If you bet the Chiefs -7, you are “laying 7 points” — the Chiefs must win by more than 7 for your bet to cash. Opposite of taking points.

Limit

Two distinct meanings in sports betting. (1) Bet limit: The maximum wager a sportsbook will accept on a given market. Sharp-origin books like Pinnacle and Circa post high limits; recreational books post lower limits. (2) Account limit: A restriction placed on a bettor’s account, reducing the maximum allowed bet size. Sportsbooks limit accounts that consistently beat the closing line. Account limits are the primary threat to long-term sharp betting profitability and agent operation.

Line

The odds, point spread, or total set by the sportsbook for a given event. “The line on the game is Chiefs -7” means the point spread is 7 points in favor of Kansas City. Lines are the sportsbook’s product — they represent the book’s assessment of probabilities, adjusted for action balancing and vig.

Line Movement

A change in the odds or spread between the opening line and the current line. Line movement is caused by betting action (both sharp and public), new information (injuries, weather), and the book’s own risk management. Tracking line movement is a core signal for sharp bettors and AI agents. See also: reverse line movement, steam move.

Lock

A bet perceived as a near-certainty. In reality, no bet is a lock — the term is most commonly used by recreational bettors and touts marketing their picks. Professional bettors avoid the concept entirely, focusing instead on expected value.

M

Market

In sports betting, a “market” refers to a specific betting option within an event. A single NFL game may have hundreds of markets: moneyline, spread, total, player props, quarter lines, and more. Each market has its own odds and limits. Prediction market equivalent: a single contract or question on Polymarket/Kalshi.

Middle

A situation where a bettor holds bets on both sides of a game at different spreads, creating a window where both bets can win. Example: you bet Team A -3 on Monday and Team B +5 on Thursday (after the line moved). If Team A wins by 4, both bets cash. Middling is a deliberate strategy that profits from line movement. Prediction market equivalent: profiting from price movement by buying low and selling high on the same contract.

Moneyline

A bet on which team will win the game outright, with no point spread involved. The moneyline is expressed in American odds: -200 means you risk $200 to win $100 (favorite); +180 means you risk $100 to win $180 (underdog). The moneyline is the simplest and most intuitive bet type. Prediction market equivalent: a binary contract — the moneyline is directly analogous to buying a Yes or No outcome token.

Mover

An event or market where the line has shifted significantly from the opening. Sharp bettors track movers to identify where professional money is being placed. Movers lists are published daily by odds tracking services and are a primary input for line movement analysis.

N

Nickel

Slang for a $500 bet. “Dropping a nickel on the game” means betting $500. Part of the traditional sportsbook slang: a nickel is $500, a dime is $1,000.

No-Vig Line (Fair Odds)

The theoretical odds if all vig were removed, representing the sportsbook’s true probability assessment. Calculated by normalizing the implied probabilities of both sides to sum to exactly 100%. If a market shows -115/+105, the no-vig equivalent is approximately -108/+108. No-vig lines from sharp sportsbooks like Pinnacle are considered the closest thing to true market-efficient odds. Prediction market equivalent: the midpoint price on a CLOB with tight spreads.

O

Odds API

A web service that provides real-time or near-real-time odds data from multiple sportsbooks in a standardized format. The Odds API (the-odds-api.com) is the most widely used service, covering 70+ sportsbooks across 40+ sports. Developers use odds APIs to feed pricing data into agent models, arb detection systems, and CLV trackers. See: Offshore Sportsbook API.

Odds Scraping

The practice of extracting odds data from sportsbook websites programmatically, typically using web scraping tools like Selenium, Puppeteer, or Playwright. Scraping is technically a violation of most sportsbooks’ terms of service and is increasingly countered by bot detection systems. Odds APIs are the legitimate alternative. See also: bot detection, rate limiting.

Off the Board

A game or market that has been temporarily removed from the betting menu, typically because of a major injury, weather event, or other uncertainty. When a key player’s status is in question, books may take the game off the board until more information is available, then re-post adjusted lines.

Opening Line

The first odds or spread posted by a sportsbook for an event. Opening lines are set by the sportsbook’s traders and reflect their initial probability assessment. The movement from opening to closing line tells the story of where sharp money landed. Early bettors (“originator” sharps) specifically target opening lines because that is where the largest mispricings exist.

Originator

A sharp bettor who is among the first to bet into opening lines, forcing the initial line movement. Originators identify mispricings before the broader market corrects. Sportsbooks respect and monitor originators because their bets are the strongest signal for where the true line should be. Prediction market equivalent: the first informed trader to move a thin market.

Over/Under

See totals.

Overround

The amount by which the total implied probability across all outcomes exceeds 100% at a single sportsbook. Represents the book’s theoretical profit margin before variance. A market with -110 on both sides has implied probabilities of 52.38% each, totaling 104.76% — the overround is 4.76%. Lower overround means better value for bettors. Prediction market equivalent: the spread between best bid and best ask, or maker/taker fees. See also: vig, hold.

P

Parlay

A single bet linking two or more selections where all must win for the bet to pay out. Parlay odds multiply — a 3-team parlay at -110 each pays roughly 6-to-1. Parlays carry higher expected vig than straight bets because the multiplicative odds amplify the embedded vig on each leg. Sportsbooks derive a significant portion of their revenue from parlay wagers. See also: accumulator, same-game parlay. Prediction market equivalent: no direct equivalent; traders must manually construct multi-position strategies.

Payout

The total amount returned to a bettor on a winning wager, including the original stake. A $100 bet at +150 has a payout of $250 ($150 profit + $100 stake). Payout speed varies widely — regulated US books typically process within 24-72 hours; offshore sportsbooks range from same-day crypto payouts to week-long bank wire processing.

Pick ‘Em (PK)

A game where neither team is favored on the spread — the line is 0 points. Both sides are priced at -110 (or similar). The moneyline may still show a slight favorite, but on the spread the matchup is considered even. Also written as “PK” or “Pick.”

Point Spread

A handicap applied to the favored team to create a theoretically even-money proposition. If the Chiefs are -7, they must win by more than 7 points for a spread bet on them to cash. If the opponent (the underdog at +7) loses by fewer than 7 points or wins outright, bets on them cash. The spread is the most popular bet type in American football and basketball. Prediction market equivalent: there is no direct equivalent, as prediction markets typically use binary outcomes rather than handicaps.

Prop Bet (Proposition Bet)

A bet on a specific occurrence within a game that is not directly tied to the final outcome. Examples: “Patrick Mahomes over/under 275.5 passing yards,” “First team to score,” “Will there be a safety?” Props can be player-based, team-based, or game-based. The prop market has exploded in recent years and now represents a major share of total handle. Props tend to have higher vig and lower limits than sides and totals.

Public Money

Wagers from recreational (“square”) bettors, which tend to follow popular teams, overs, and favorites. Public money is tracked as a percentage of total bets (not total dollars). A game receiving 75% of bets on one side but only 50% of dollars indicates sharp money opposing the public. See also: sharp, square, reverse line movement.

Push

A bet that results in a tie against the spread or total. If the spread is -7 and the favorite wins by exactly 7, the bet pushes and stakes are returned. Pushes are the reason half-point spreads (3.5, 7.5) exist — they eliminate the possibility of a push on key numbers.

R

Rate Limiting

Restrictions on how frequently an API or website can be queried. Sportsbook APIs and odds data providers impose rate limits to prevent server overload and abuse. A typical rate limit might be 500 requests per minute. Agents must implement rate-limiting logic (exponential backoff, request queuing) to avoid being blocked. Prediction market equivalent: Polymarket and Kalshi both enforce per-second and per-minute rate limits on their APIs. See: Polymarket Rate Limits Guide.

Regulated Sportsbook

A sportsbook operating with a valid license from a government regulatory body. In the US, this means state-by-state licensing (DraftKings, FanDuel, BetMGM, Caesars). Regulated books offer consumer protections, required fund segregation, and dispute resolution but also enforce strict KYC, geolocation, and aggressive account limiting of winning players. Contrast with offshore sportsbook.

Reverse Line Movement (RLM)

A situation where the line moves in the opposite direction of where the majority of bets are being placed. Example: 80% of bets are on the Chiefs -3, but the line moves from -3 to -2.5. This indicates sharp money on the other side — the minority of bets (by count) represents the majority of dollars. RLM is one of the strongest signals for sharp-side identification. Prediction market equivalent: the price moving against majority sentiment.

Rollover (Playthrough)

The wagering requirement attached to a sportsbook bonus before winnings can be withdrawn. A $500 bonus with a 10x rollover requires $5,000 in total wagers before withdrawal. Some offshore books apply rollover to both the bonus and the deposit amount. Understanding rollover math is important for evaluating bonus value and is a common automation target for agent systems.

Round Robin

A bet structure that creates every possible parlay combination from a selected group of picks. Selecting 4 teams in a round robin creates multiple 2-team and 3-team parlays automatically. Round robins reduce risk versus a single large parlay by allowing partial wins if some legs lose.

S

Same-Game Parlay (SGP)

A parlay where all legs come from the same event. Example: Chiefs moneyline + Mahomes over 250 passing yards + game total over 48.5 — all on a single Kansas City game. SGPs are priced using correlated probability models rather than naive multiplication, and they carry significant vig. SGPs have become the fastest-growing product at US sportsbooks.

Selenium

An open-source browser automation framework used by developers to interact with web pages programmatically. In the sports betting context, Selenium (and alternatives like Puppeteer and Playwright) are used for odds scraping and automated bet placement on sportsbooks that lack APIs. Sportsbooks actively detect and block Selenium-driven automation. See also: bot detection, odds scraping.

Sharp

A professional, winning bettor whose wagers influence sportsbook lines. Sharps bet large amounts based on statistical models, proprietary data, or deep domain expertise. Sportsbooks respect sharp action as a pricing signal but also limit sharp accounts to manage risk. Sharp money is the primary driver of line movement. Prediction market equivalent: a whale or informed trader who consistently moves market prices. See: Sharp Betting.

Sharp Action

Bets placed by sharp bettors. Sportsbooks track which accounts are sharp and use their betting patterns to adjust lines. When a sharp account bets one side, the book often moves the line immediately — even on a single bet. Sharp action is the most reliable signal for line movement analysis.

Square

A recreational or casual bettor who bets based on gut feeling, team loyalty, or popular narratives rather than statistical analysis. Square money tends to favor favorites, overs, and high-profile teams. Sportsbooks profit disproportionately from square bettors. Opposite of sharp.

Steam Move

A sudden, sharp line movement that occurs simultaneously across multiple sportsbooks, driven by coordinated or simultaneous sharp action. Steam moves happen within seconds and represent the market rapidly repricing based on new information or a major sharp bet. Steam move detection is a core feature of real-time odds monitoring systems.

Straight Bet

A single wager on one outcome — a moneyline, spread, or total. Straight bets are the simplest and lowest-vig bet type. Professional bettors place almost exclusively straight bets because the expected value is clearer and the vig is lower than exotic wagers.

Syndicate

An organized group of sharp bettors who pool capital and coordinate wagers across multiple sportsbook accounts. Syndicates operate as the institutional investors of sports betting. They use multiple accounts to place large bets without moving lines prematurely and to circumvent individual account limits. Prediction market equivalent: a trading desk or fund that operates multiple wallets.

T

Taking Points

Betting on the underdog and receiving the point spread advantage. If you bet the Jets +7, you are “taking 7 points” — the Jets can lose by up to 6 points and your bet still cashes. Opposite of laying points.

Teaser

A type of parlay where the bettor receives a more favorable point spread on each leg in exchange for lower odds. A standard 6-point teaser in football moves each spread by 6 points (e.g., -7 becomes -1, +3 becomes +9). All legs must still win. Certain teaser strategies crossing key numbers (particularly 3 and 7 in football) have historically shown positive expected value.

The Odds API

The most widely used commercial odds data service for developers, providing real-time and historical odds from 70+ sportsbooks via REST API. Plans range from free (limited requests) to paid tiers supporting high-frequency polling. The Odds API is the standard data source for building sports betting bots, arbitrage scanners, and CLV trackers. See: Offshore Sportsbook API integration guide.

Ticket Percentage vs. Money Percentage

Two different measures of betting activity on a given side. Ticket percentage counts the number of individual bets; money percentage counts total dollars wagered. When these diverge (e.g., 80% of tickets but only 40% of money on one side), it signals that sharps and squares are on opposite sides. This divergence is the foundation of reverse line movement analysis.

Totals (Over/Under)

A bet on whether the combined final score of both teams will be over or under a number set by the sportsbook. If the total is set at 48.5 for an NFL game, you bet on whether both teams will combine for 49+ points (over) or 48 or fewer (under). Totals have their own line movement ecosystem separate from sides. Prediction market equivalent: a numeric threshold contract like “Will Bitcoin close above $100K?”

Tout

A person who sells sports betting picks, typically through subscription services or social media. Tout track records are frequently fabricated or selectively reported. The industry has a well-documented problem with tout fraud — claiming winning records by retroactively editing or selectively sharing results. See also: handicapper.

U

Unit

A standardized measure of bet size, typically 1% of a bettor’s bankroll. A bettor with a $10,000 bankroll has a unit size of $100. Using units rather than dollar amounts normalizes bet sizes for comparison and bankroll management. “I’m up 15 units on the season” is more meaningful than “I’m up $1,500” without knowing the bankroll. Prediction market equivalent: percentage of portfolio risked per trade.

V

Vig (Vigorish)

The commission built into betting odds that guarantees the sportsbook profit. Standard vig on a spread bet is -110 on each side, meaning the book collects $110 from losers but only pays $100 to winners — keeping $10 per $210 wagered (4.76%). Vig is baked into every odds format: American, decimal, and fractional. Reduced-vig books (like Pinnacle at -104/-104 on some markets) offer better value. Prediction market equivalent: maker/taker fees on exchanges like Polymarket (typically 0-2%) or Kalshi. See also: juice, overround, hold.

Void Bet

A bet that is canceled and the stake returned. Bets may be voided if an event is canceled, if a key participant is scratched (in some prop bet rules), or if the sportsbook detects a pricing error. Voided bets in parlays typically reduce the parlay to the remaining legs rather than canceling the entire wager.

W

Wager

A synonym for bet. The terms are used interchangeably in sports betting.

Wiseguy

Another term for a sharp bettor. Wiseguy is traditional Las Vegas sportsbook slang for a professional bettor who consistently beats the closing line. The term is less common in modern usage but still appears in industry writing.

Withdrawal

Moving funds out of a sportsbook account. Withdrawal methods, speeds, and minimums vary by sportsbook. Regulated US books typically require the same method used for deposit. Offshore sportsbooks commonly process withdrawals via cryptocurrency (often the fastest option) or bank wires (typically 5-10 business days). Prediction market equivalent: withdrawing USDC to a wallet or cashing out from an exchange.

Key Concepts for Developers and Agents

This section highlights terms that are especially relevant for developers building automated systems and AI agents for sports betting.

Account Limiting and Management

Sportsbooks monitor betting patterns and limit accounts that show consistent sharp behavior. Key indicators that trigger limits include: beating the closing line repeatedly, betting into opening lines before they are widely available, rapid bet placement suggesting automation, and taking max limits consistently. Account longevity strategies include mixing recreational bets with sharp wagers, varying timing and bet sizes, using multiple sportsbook accounts, and avoiding obvious bot patterns. For more on building agent systems that account for these realities, see AI Sports Betting Agents.

Odds Data Pipeline

The standard architecture for feeding sportsbook data into an AI agent or trading system. The pipeline typically consists of: (1) a data ingestion layer pulling from an odds API or scraping system, (2) a normalization layer converting all odds to a common format (usually implied probability), (3) a storage layer for historical odds data and line movement tracking, and (4) a model layer that consumes the normalized data for pricing, arbitrage detection, or CLV analysis.

Prediction Market Crossover

Sports betting and prediction markets are converging. Many sportsbook concepts map directly to prediction market equivalents — moneylines are binary contracts, vig is the spread or fee, handle is volume, and sharps are informed traders. Developers building agents that operate across both ecosystems need fluency in both vocabularies. For the prediction market side of this glossary, see the Agent Betting Glossary and the Sports Betting vs. Prediction Markets comparison.

Further Reading