ParlayMath

Sports Betting Glossary

A comprehensive A-Z reference of sports betting terms and concepts.

A

Action

A wager of any kind. Having 'action' means having a bet in play.

Against the Spread (ATS)

Betting on the point spread rather than the moneyline. A team that covers the spread wins ATS.

Arbitrage

Placing bets on all possible outcomes of an event at different sportsbooks to guarantee a profit regardless of the result.

B

Bad Beat

A bet that appears to be winning but loses due to a late or unexpected turn of events.

Bankroll

The total amount of money a bettor has set aside specifically for sports betting.

Bonus

Promotional offer from a sportsbook, often matching a percentage of your initial deposit.

Book / Bookmaker

A person or organization that accepts bets on sporting events and sets odds. Also called a sportsbook.

Buying Points

Paying extra juice (worse odds) to move the point spread or total in your favor.

C

Chalk

The favorite in a game or event. Betting chalk means betting on the favorite.

Closing Line

The final odds posted before the game begins. Consistently beating the closing line is a sign of a sharp bettor.

Contrarian

A betting strategy that involves wagering against the public consensus.

Cover

To win against the point spread. A team covers when they beat the spread.

D

Dead Heat

When two or more competitors tie, and payouts are divided proportionally.

Decimal Odds

Odds format popular in Europe showing the total payout per $1 wagered (e.g., 2.50 means $2.50 back on a $1 bet).

Dog / Underdog

The team or player expected to lose, reflected by positive American odds (e.g., +200).

E

Edge

A bettor's advantage over the sportsbook, typically expressed as a percentage of expected profit.

Even Money

A bet where the payout equals the stake. American odds of +100 or decimal odds of 2.00.

Exotic Bet

Any wager other than a straight bet, including parlays, teasers, and props.

Expected Value (EV)

The average amount a bettor can expect to win or lose per bet over the long run. Positive EV means profitable.

F

Favorite

The team or player expected to win, shown with negative American odds (e.g., -150).

Fixed Odds

Odds that are locked in at the time of the bet and do not change regardless of later market movement.

Fractional Odds

Odds format popular in the UK expressed as a fraction (e.g., 5/1 means $5 profit on a $1 bet).

Futures

Bets on events that will be decided in the future, such as which team will win the championship.

G

Grand Salami

A bet on the total combined score of all games on a given day in a specific sport.

H

Handicap

A point advantage given to the underdog (or disadvantage to the favorite) to equalize betting. Same as a point spread.

Handle

The total amount of money wagered on an event or at a sportsbook over a given period.

Hedge

Placing a bet on the opposite side of your original wager to reduce risk or guarantee a profit.

Hold

The percentage of total wagers the sportsbook keeps as profit. Calculated from the overround/vig.

Hook

A half-point in the spread (e.g., 3.5 instead of 3). Getting or laying the hook can determine a push vs. a win/loss.

I

Implied Probability

The probability of an outcome as suggested by the odds. Calculated as 1 / decimal odds.

In-Game Betting

Also called live betting. Placing bets on an event while it is in progress, with odds updating in real time.

J

Juice

Another term for the vig or vigorish. The commission the sportsbook charges on bets.

K

Kelly Criterion

A mathematical formula for calculating the optimal bet size based on your edge and the odds offered.

Key Number

Common margins of victory in a sport (e.g., 3 and 7 in football) that are important when evaluating spreads.

L

Lay

To bet on the favorite, or to bet that an outcome will NOT happen (common in exchanges).

Limit

The maximum amount a sportsbook will accept on a single wager.

Line

The odds or point spread on a game. 'Getting a good line' means getting favorable odds.

Line Movement

Changes in the odds or point spread as a result of betting action, news, or other factors.

Lock

A bet that is considered a sure winner. In reality, there are no true locks in sports betting.

M

Middle

Betting both sides of a game at different spreads with a chance of both bets winning.

Moneyline

A bet on which team will win straight up, without a point spread. Expressed as American odds.

Mush

A bettor believed to bring bad luck. Also called a cooler.

N

No Action

A bet that is canceled and the wager is returned, often due to a postponed or canceled event.

O

Odds

The ratio or number that indicates the potential payout of a bet relative to the stake.

Off the Board

A game or event that sportsbooks are not currently accepting bets on.

Over/Under (Total)

A bet on whether the combined score of both teams will be over or under a specified number.

Overround

The total implied probability exceeding 100%, representing the bookmaker's built-in margin.

P

Parlay

A single bet combining two or more selections. All selections must win for the parlay to pay out.

Pick'em

A game where neither team is favored, with the spread set at 0.

Point Spread

The margin of victory set by oddsmakers. The favorite must win by more than the spread to cover.

Prop Bet (Proposition)

A bet on a specific occurrence within a game, not directly tied to the final outcome (e.g., player stats).

Public Money

Bets placed by casual bettors, as opposed to sharp or professional bettors.

Push

When the result exactly matches the spread or total, and the bet is refunded.

R

Return on Investment (ROI)

The net profit expressed as a percentage of total amount wagered over time.

Reverse Line Movement

When the odds move in the opposite direction of where the public is betting, indicating sharp action.

Risk of Ruin

The probability that a bettor will lose their entire bankroll.

Round Robin

A series of parlays created from a larger list of selections, covering multiple combinations.

Run Line

The point spread in baseball, typically set at -1.5 / +1.5 runs.

S

Sharp

A professional or highly skilled bettor. Sharp money can move lines.

Spread

Short for point spread. The number of points by which the favorite is expected to win.

Square

A recreational or casual bettor, as opposed to a sharp.

Steam Move

A sudden, drastic line movement caused by heavy betting from sharps or syndicates.

Straight Bet

A single wager on one game or event, as opposed to a parlay or teaser.

T

Teaser

A type of parlay where the bettor can adjust the point spread in their favor in exchange for reduced odds.

Ticket

The record of a bet, whether physical or digital.

Total

The combined score of both teams. Bettors wager on whether the actual total will be over or under this number.

Tout

A person who sells betting picks or predictions.

True Odds

The actual probability of an outcome, without the bookmaker's margin factored in.

U

Unit

A standard bet size, typically 1-5% of a bettor's bankroll. Used to standardize bet sizing.

V

Value

When the odds offered are higher than the true probability warrants, creating a positive expected value bet.

Vig / Vigorish

The commission or fee charged by a sportsbook on each bet. Standard vig is -110 on each side.

W

Wager

Any bet placed on a sporting event.

Wiseguy

Another term for a sharp or professional sports bettor.