From parlays to steam moves, American sports betting runs on its own vocabulary, shaped by decades of Vegas sportsbook culture now applied to the regulated online market. This glossary covers the terms you'll actually encounter.

Whether you're reading a bet slip, a sportsbook's promo terms or a betting analyst's breakdown, these are the words that come up constantly across US sports betting. Entries are grouped alphabetically below.

A

Action — Any bet placed, or general betting activity. "Getting some action" simply means placing a wager.

ATS (Against The Spread) — A team's record when measured against the point spread rather than straight wins and losses — a team can be well above .500 straight-up but have a losing ATS record if they've been covering inconsistently.

B

Bad Beat — A bet that appeared certain to win but lost due to a late, often unlikely turn of events — a backdoor cover in the final seconds, for instance.

Bankroll — The total amount of money set aside specifically for betting, separate from general spending money. Managing bankroll size relative to individual bet size is a core part of betting sustainably.

Book — Short for sportsbook, the operator taking the bet.

C

Chalk — The favorite in a given matchup, generally considered the safer but lower-paying side. Explained further in our odds guide.

Circle Game — A game a sportsbook has flagged with reduced betting limits, typically due to uncertainty around a key player's availability or unusual line movement.

Cover — Winning against the point spread — a favorite "covers" by winning by more than the spread, an underdog "covers" by losing by less than the spread or winning outright.

D

Dog — Short for underdog, the side priced with plus-money odds as the side considered less likely to win.

E

Edge — A genuine, calculable advantage a bettor believes they have over the market's posted odds, based on information or analysis the bettor thinks the book hasn't fully priced in.

Even Money — Odds where the payout equals the stake — a $100 bet at even money wins $100 profit, represented as +100 in American odds format.

F

Favorite — The team or player expected to win, carrying negative moneyline odds and typically giving points on the spread.

Futures — A long-term bet placed on an outcome that won't be determined for weeks or months, such as a team to win a championship before the season starts. Explained further in our odds guide.

G

Grand Salami — A bet on the total combined goals or runs scored across every game on a given day's slate, common in hockey and baseball specifically.

H

Handle — The total amount of money wagered on a given event or across a sportsbook over a period, used as a measure of betting volume rather than profit.

Hook — The extra half-point on a spread or total, used specifically to eliminate the possibility of a push.

J

Juice — See Vig below — the two terms are used interchangeably across most of the US market.

L

Layoff — A bet a sportsbook places with another book specifically to offset excessive one-sided action on a particular outcome, reducing its own liability.

Line — The current odds or point spread for a given market, used generally across spread, total and moneyline markets alike.

Line Shopping — Comparing the same bet across multiple sportsbooks to find the most favorable price before placing it.

Live Betting — Wagering on a game already in progress, with odds updating continuously. Covered in full in our live betting guide.

Lock — Slang for a bet considered a certainty — used colloquially and not to be taken literally, since no sports bet is genuinely guaranteed.

Longshot — A selection considered unlikely to win, carrying substantial plus-money odds.

M

Middle — A situation where a bettor wins both sides of a bet placed at two different point spreads on the same game, achieved by betting one side early and the other after the line has moved favorably.

Moneyline — A straight bet on which team wins outright, with no point spread involved. Explained in full in our odds guide.

O

Off the Board — A game or market temporarily unavailable for betting, often due to injury uncertainty or unusual circumstances affecting the book's ability to set a fair line.

Original Line — The point spread or total a sportsbook first posts for a game, before any market movement.

Over/Under — See Total below.

P

Parlay — A single bet combining multiple selections, where all must win for the bet to pay out, with odds multiplying across every leg. Explained in full in our odds guide.

Pick'em — A game with no favorite on the moneyline, both sides priced close to even odds.

Point Spread — A market that handicaps the favorite by a set number of points, designed to balance the perceived probability of both sides. Explained in full in our football betting markets guide.

Press — Increasing your bet size, often following a win, sometimes used to describe chasing a loss with a larger subsequent bet.

Prop Bet — A wager on a specific occurrence within a game not directly tied to the final score, commonly a player's individual statistical performance. Explained further in our football betting markets guide.

Puck Line — Hockey's version of the point spread, almost always set at 1.5 goals given the sport's typically low scoring.

Push — A tie against the point spread or total, resulting in the bet being voided and the stake returned.

R

Run Line — Baseball's version of the point spread, almost always set at 1.5 runs given the sport's typically close scoring margins.

S

Sharp — A bettor widely regarded as skilled and consistently profitable, whose action sportsbooks sometimes track closely and adjust lines in response to.

Spread — See Point Spread above.

Steam — Rapid, significant line movement across multiple sportsbooks simultaneously, often interpreted as a signal that sharp money is moving on one side of a market.

Straight Bet — A single wager on one outcome, as opposed to a parlay or teaser combining multiple selections.

Sucker Bet — A wager considered to carry disproportionately poor value for the bettor relative to the sportsbook's advantage, often applied to certain prop or novelty bets.

T

Teaser — A bet combining multiple legs while shifting the spread or total in the bettor's favor across all of them, in exchange for reduced payout odds. Explained in full in our football betting markets guide.

Total — A bet on the combined final score of both teams, priced above or below a number set by the sportsbook.

U

Underdog — The team or player considered less likely to win, carrying positive moneyline odds and typically receiving points on the spread.

Unit — A standardized measure of bet size used by bettors to track performance proportionally rather than in fixed dollar amounts, letting results be compared consistently regardless of individual bankroll size.

V

Vig — Short for vigorish, the sportsbook's built-in commission, most visible on a standard -110 spread bet. Explained in full in our odds guide.

W

Wiseguy — Another term for a sharp bettor, generally used interchangeably with "sharp."

Frequently asked questions

What's the difference between juice and vig?

Nothing — they're the same concept, the sportsbook's built-in commission, with "vig" (short for vigorish) and "juice" used interchangeably depending on regional and personal preference.

What does it mean when a sportsbook takes a game "off the board"?

The book has temporarily removed that game or market from betting, typically due to uncertainty (an injury report pending, unusual line activity) that makes it unwilling to offer a confident price until the situation clarifies.

Is a "lock" actually guaranteed to win?

No — it's casual slang expressing high confidence, not a literal guarantee. No sports bet carries a certain outcome, regardless of how heavily favored a side appears.

Why do hockey and baseball use "puck line" and "run line" instead of "point spread"?

Both terms describe the same underlying concept — a market that handicaps the favorite by a fixed margin — but are branded specifically for their sport, reflecting the standard 1.5-goal or 1.5-run margin typical in those lower-scoring games.

What's a "middle," and is it actually risk-free?

A middle occurs when a bettor wins both sides of a bet placed at two different lines on the same game, but it requires the final result to land in a specific narrow range between those two lines — it's a genuine opportunity when it lines up, not a risk-free strategy available on demand.

Where can I find more detail on parlays or the point spread specifically?

Both have dedicated guides on this site covering the mechanics in far more depth than a glossary entry allows.

This guide is for educational purposes. Betting involves financial risk. 21+ and physically present in a state where the operator is licensed. Gambling problem? Call 1-800-MY-RESET or 1-800-522-4700 (National Problem Gambling Helpline). Information correct as of October 2026.