Sports betting glossary
Plain-English definitions of the terms you'll see on a sportsbook line, in our calculators, and across the site. Each entry links to the related tool and adjacent concepts.
A
Action
A live, settled bet with money on the line — also used to describe overall betting volume on a market.
Alt Line
An "alternative" spread or total at a different number than the main line — repriced for the changed risk.
American Odds
The +/- odds format used by US sportsbooks, where the number shows profit on a $100 base.
Arbitrage
Betting both sides of a market across different sportsbooks at prices that guarantee profit regardless of outcome.
B
C
Chalk
The favorite — usually the popular pick, often heavy chalk means a heavy favorite.
Closing Line Value
The gap between the price you bet and the line that closes — the truest single signal of whether you're a sharp bettor.
Correlated Parlay
A parlay where one leg's outcome makes another leg more likely — usually blocked or repriced by sportsbooks.
Cover
When a team beats the spread — wins by more than the favorite line, or loses by less than the underdog line.
D
E
F
Fade
Betting against a side — usually against a public lean, an analyst's pick, or a popular bettor's play.
Fractional Odds
The traditional UK odds format — a fraction showing profit-to-stake ratio.
Futures
A bet on a long-term outcome — championship winner, season MVP, regular-season win totals — placed weeks or months in advance.
H
I
J
K
L
Limits
The maximum bet a sportsbook will accept on a market — varies by market liquidity, customer profile, and time-to-game.
Line Shopping
The practice of comparing odds across multiple sportsbooks before placing a bet — the single highest-leverage habit a retail bettor can adopt.
Lock
Slang for a bet a bettor is supremely confident in — almost always misleading, since real locks would be priced as such.
M
P
Parlay
A single bet that combines multiple wagers — every leg must win for the bet to cash.
Prop Bet
A bet on something other than the final outcome — a player stat line, a first-quarter score, an in-game event.
Public Side
The side of a line that the majority of the betting public is on — usually the favorite, the popular team, or the over.
Push
A bet that ties the spread or total exactly — the stake is refunded, no win, no loss.
R
S
Same-Game Parlay
A parlay made up entirely of legs from a single game — priced by the book, not by naive multiplication.
Sharp
A bettor who consistently makes +EV plays — disciplined, model-driven, and respected by the books.
Spread
A points-based handicap that adjusts a game's expected margin to make both sides roughly equal bets.
Square
A casual or recreational bettor — typically bets favorites, public sides, parlays, and longshots based on narratives instead of math.
Steam
A sudden, sharp line movement caused by sharp action — books move the line aggressively to balance the new exposure.