Guides
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About This Glossary
This glossary covers the essential terms you will encounter across sports betting, from basic odds formats to advanced strategy concepts.
Each definition includes a practical example so you can see how the term applies in real betting scenarios. Terms are organized alphabetically for quick reference whether you are a beginner building your foundation or an experienced bettor brushing up on strategy terminology.
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Betting Terms A-Z
term: Account Limiting
definition: When a sportsbook restricts your maximum bet size or removes access to promotions, typically because your betting pattern indicates you are a winning bettor.
example: After hitting several sharp lines, your max bet on player props drops from $500 to $10.
term: Alt Line
definition: An alternative spread or total that differs from the main posted line, offering adjusted odds in exchange for a more or less favorable number.
example: The main spread is Chiefs -3 (-110). An alt line of Chiefs -1.5 might be priced at -175.
term: American Odds
definition: The standard odds format used in the United States. Positive numbers show how much you win on a $100 bet, and negative numbers show how much you must bet to win $100.
example: An underdog at +200 pays $200 profit on a $100 wager. A favorite at -150 requires a $150 wager to profit $100.
term: Arbitrage
definition: A strategy where you bet on all outcomes of an event across different sportsbooks at odds that guarantee a profit regardless of the result.
example: Book A has Team X at +150 and Book B has Team Y at +110 on a two-way market. Proper stake allocation locks in a 2.3% guaranteed return.
term: Bankroll
definition: The total amount of money you have set aside specifically for sports betting, kept separate from your personal finances.
example: You deposit $2,000 across your sportsbook accounts as your dedicated betting bankroll for the NFL season.
term: Bonus Bet
definition: A promotional wager from a sportsbook where only the profit is returned if the bet wins, not the original stake amount.
example: You receive a $100 bonus bet and place it on +200 odds. If it wins, you collect $200 in profit but the $100 stake is not returned.
term: CLV (Closing Line Value)
definition: The difference between the odds at which you placed your bet and the final odds at market close. Consistently beating the closing line is the strongest indicator of long-term profitability.
example: You bet a team at +130 and the line closes at +115. You captured positive CLV, meaning you got a better price than the final market.
term: Closing Line
definition: The final odds offered on a market just before the event begins. Considered the most efficient and accurate line because it reflects all available information.
example: The Bills opened at -3 and the closing line moved to -4.5 after sharp money came in on Buffalo.
term: Decimal Odds
definition: An odds format common internationally that represents the total payout per dollar wagered, including the original stake.
example: Decimal odds of 2.50 mean a $100 bet returns $250 total, which is $150 in profit plus your $100 stake.
term: Expected Value (EV)
definition: The average amount you can expect to win or lose per bet over the long run if you placed the same wager repeatedly.
example: A bet at +120 on an outcome with a true 50% probability has an EV of +10%. For every $100 wagered, you expect to profit $10 on average.
term: Fair Odds
definition: Odds that precisely reflect the true probability of an outcome with no bookmaker margin built in. Also referred to as no-vig odds.
example: If a coin flip is 50/50, fair odds would be +100 on both sides. Any line shorter than +100 includes a bookmaker margin.
term: Free Bet
definition: A promotional offer from a sportsbook that allows you to place a wager without risking your own money. Some free bets return the stake on a win, while others return only the profit.
example: A sportsbook offers a $50 free bet for signing up. You use it on a +200 line and win, collecting $100 in profit.
term: Futures
definition: Bets placed on the outcome of an event that will be determined at a later date, such as a championship winner or season award.
example: In October you bet the Celtics to win the NBA Championship at +600. The bet does not settle until the Finals end in June.
term: Handle
definition: The total dollar amount wagered on a particular event, market, or across an entire sportsbook over a given period.
example: The Super Bowl handle in Nevada exceeded $200 million, reflecting the total volume of money bet on the game.
term: Hedge
definition: Placing a bet on the opposite side of an existing wager to reduce risk or lock in a guaranteed profit.
example: You bet the Eagles to win the Super Bowl at +2000 before the season. Once they make the game, you bet the opposing team to guarantee profit regardless of outcome.
term: Hold Percentage
definition: The total margin a sportsbook builds into a market across all outcomes. A lower hold means more favorable odds for bettors.
example: A market with -105 on both sides has a 2.4% hold. A market with -110 on both sides has a 4.5% hold.
term: Implied Probability
definition: The probability of an outcome as suggested by the betting odds, including the sportsbook's built-in margin.
example: Odds of -150 imply a 60% probability of winning. Odds of +200 imply a 33.3% probability of winning.
term: Kelly Criterion
definition: A mathematical formula used to determine the optimal bet size based on your edge and bankroll, maximizing long-term growth while managing risk of ruin.
example: With a 55% win probability on a -110 line, full Kelly suggests risking 5.5% of your bankroll. Many bettors use fractional Kelly (one-quarter to one-half) for a more conservative approach.
term: Limit
definition: The maximum amount a sportsbook will allow you to wager on a particular bet or market.
example: A sharp book may accept $10,000 on an NFL spread, while a retail book may limit you to $500 on the same market.
term: Line Movement
definition: A change in the odds or point spread for a market after the line is first posted, driven by betting volume, sharp action, or new information.
example: The Lakers opened at -4 and moved to -6 after sharp bettors hammered the line early in the week.
term: Live Betting
definition: Placing wagers on an event that is already in progress, with odds updating in real time based on the current game state.
example: A team trailing 14-0 at halftime might be available at +300 on the live moneyline, offering value if you believe they can rally.
term: Low Hold
definition: A market where the combined vig across sportsbooks is unusually small, allowing bettors to cover both sides at minimal cost. Useful for converting bonus bets or meeting rollover requirements.
example: Book A has Team X at +102 and Book B has Team Y at +102. The combined hold is under 1%, making it ideal for bonus bet conversion.
term: Middle
definition: A situation where you can bet both sides of a market at different numbers, creating a window where both bets could win simultaneously.
example: You bet Team A -2.5 on Book A and Team B +4.5 on Book B. If Team A wins by 3 or 4, both bets cash.
term: Moneyline
definition: A straight-up bet on which team or player will win the game, with no point spread involved.
example: The Yankees are -180 on the moneyline and the Red Sox are +155. Betting the Yankees means they simply need to win.
term: No-Sweat Bet
definition: A sportsbook promotion where you receive a bonus bet refund if your qualifying wager loses, effectively giving you a second chance.
example: A $500 no-sweat bet on the Packers. If the Packers lose, you get a $500 bonus bet back to use on a future wager.
term: No-Vig Odds
definition: Odds with the sportsbook's margin removed, representing a cleaner estimate of true probability. Used as a benchmark for identifying value.
example: A market shows -150/+130. After removing the vig, the no-vig line is approximately -140/+140, reflecting a 58.3% true probability for the favorite.
term: Opening Line
definition: The first set of odds posted by a sportsbook for an event, before any betting action influences the numbers.
example: The opening line on the Chiefs game is -3. By kickoff, the line has moved to -4.5 based on early sharp action.
term: Overround
definition: The total implied probability across all outcomes in a market, which exceeds 100% because of the sportsbook's built-in margin.
example: A two-way market at -110/-110 has implied probabilities of 52.4% each, totaling 104.8%. The 4.8% above 100% is the overround.
term: Parlay
definition: A single bet that combines two or more individual selections. All legs must win for the parlay to pay out, but the combined odds are higher than betting each individually.
example: A three-leg parlay combining Chiefs -3, Lakers ML, and Yankees ML at +600 pays $600 on a $100 wager, but all three must hit.
term: Positive EV
definition: A bet where your expected long-term return is positive, meaning the odds being offered are better than the true probability warrants.
example: A sportsbook offers +150 on an outcome with a true probability of 45%. Since fair odds would be +122, this bet has positive expected value.
term: Profit Boost
definition: A sportsbook promotion that increases the payout odds on a qualifying bet by a specified percentage.
example: A 50% profit boost on a +200 line turns it into +300. A $50 bet now profits $150 instead of $100 if it wins.
term: Prop Bet
definition: A wager on a specific occurrence or statistic within a game, rather than the final outcome. Common props include player stats, team totals, and game events.
example: Betting that Patrick Mahomes will throw over 2.5 touchdown passes at -120.
term: Risk of Ruin
definition: The probability of losing your entire bankroll given your bet sizing, edge, and variance. Proper bankroll management minimizes this risk.
example: Betting 20% of your bankroll per wager with a 3% edge gives a significant risk of ruin. Dropping to 2% per wager dramatically reduces it.
term: ROI (Return on Investment)
definition: Your net profit expressed as a percentage of total money wagered. A key performance metric for evaluating betting success over time.
example: You wagered $10,000 over a month and profited $350. Your ROI is 3.5%.
term: Sharp
definition: A sophisticated, professional bettor whose action is respected by sportsbooks and often influences line movement.
example: Sharp bettors moved the line from -3 to -4.5 within minutes of it being posted, signaling strong conviction on that side.
term: Spread (Point Spread)
definition: A handicap applied to the favored team to level the betting field. The favorite must win by more than the spread, while the underdog can lose by less than the spread or win outright.
example: The Bills are -6.5 against the Jets. A bet on Buffalo covers only if they win by 7 or more points.
term: Square
definition: A recreational or casual bettor who typically bets based on popular opinion, team loyalty, or surface-level analysis rather than data-driven strategy.
example: Square bettors tend to load up on favorites and overs, which is why sharps often find value on underdogs and unders.
term: Steam Move
definition: A sudden, dramatic shift in a betting line caused by a large volume of sharp money hitting the market at multiple sportsbooks simultaneously.
example: A steam move pushes the Dolphins from -2.5 to -4 across every major book within seconds, indicating coordinated sharp action.
term: Total (Over/Under)
definition: A bet on whether the combined score of both teams in a game will be over or under a number set by the sportsbook.
example: The total is set at 48.5 for an NFL game. Betting the over means you need the combined score to be 49 or more.
term: True Probability
definition: The actual likelihood of an outcome occurring, independent of any sportsbook margin. Estimating true probability is the foundation of identifying value bets.
example: A sportsbook offers -150 (60% implied), but your model estimates the true probability at 55%. The discrepancy suggests the line is off.
term: Unit
definition: A standardized bet size representing a fixed percentage of your bankroll, used to normalize results and compare performance across different bankroll sizes.
example: With a $5,000 bankroll and 1% unit size, one unit equals $50. A 3-unit bet would be $150.
term: Vig (Juice)
definition: The commission a sportsbook charges on each bet, built into the odds. This is how sportsbooks generate revenue regardless of the event outcome.
example: Standard vig is -110 on both sides of a spread. You risk $110 to win $100, and the extra $10 represents the vig.
term: Yield
definition: Your average profit per unit wagered over a sample of bets, expressed as a percentage. Similar to ROI but commonly used in per-bet analysis.
example: Over 200 bets at 1 unit each, you profited 12 units. Your yield is 6%, meaning you averaged +0.06 units per bet.