Sports Betting Glossary: Terms Explained

Betting has a dense vocabulary, much of it borrowed from bookmaking and much of it used loosely. Everything below is grouped by what it describes rather than alphabetically, so related terms sit together and the structure of the subject is visible.

On this page

Odds And Prices
Bet Types
Line Movement And Market Terms
Money And Staking
Handicapping Terms
Slang And Shorthand
Where To Go Next

Odds And Prices

The vocabulary of the number itself. Everything in this section describes a price rather than a bet type.

Odds And Prices.
Term	Definition
American odds	The default US format. A minus number is the stake required to win 100; a plus number is the profit on a 100 stake.
Decimal odds	The total return per unit staked, including the stake. 2.00 is an even-money price.
Fractional odds	The profit relative to the stake, written as a fraction. 5/2 returns 250 profit on 100.
Implied probability	The win probability a price corresponds to. −110 implies 52.4%.
Break-even rate	The win percentage required to profit at a given price. 52.4% at −110.
Vig	The bookmaker's built-in margin, also called juice. The reason both sides of a market total more than 100%.
Juice	Interchangeable with vig, though often used to mean the specific price on a play, as in 'minus 115 juice'.
Hold	The share of total money wagered a book expects to keep on a market.
Reduced juice	A market priced with a smaller margin than standard, typically −105 rather than −110.
No-vig line	A price with the margin removed proportionally, used as an estimate of the market's true probability.
Even money	A price of +100, where the profit equals the stake.
Dime	1,000 in bettor shorthand. A 'dime bet' is a 1,000 wager.
Nickel	500 in bettor shorthand.
Dollar	100 in bettor shorthand, which is why the shorthand causes confusion.

Bet Types

The instruments available on a typical board, from the three core markets to the derivatives built on top of them.

Bet Types.
Term	Definition
Moneyline	A bet on which team wins outright, with no margin requirement.
Point spread	A handicap applied to the favourite so both sides are priced near even money.
Total	A bet on the combined score of both teams, also called the over/under.
Over	A bet that the combined score exceeds the posted total.
Under	A bet that the combined score falls below the posted total.
Run line	Baseball's fixed 1.5-run spread, replacing the variable spread of football and basketball.
Puck line	Hockey's fixed 1.5-goal spread.
Parlay	A single bet combining multiple selections where every leg must win.
Same game parlay	A parlay whose legs come from one game, priced with correlation adjustments.
Teaser	A parlay where each spread is moved in your favour in exchange for a shorter price.
Round robin	A set of smaller parlays generated automatically from a list of selections.
Prop	A bet on an occurrence within a game rather than its result, most often a player statistic.
Alternate line	A spread or total offered away from the main number at an adjusted price.
Future	A bet on a season-long outcome such as a championship or win total.
Live bet	A wager placed after the event has started, on continuously updated prices.
First five innings	A baseball market settling on the score after five innings, isolating the starting pitchers.
Half or quarter bet	A market settling on a segment of the game rather than the full result.
Push	A tie between the result and the number, which voids the bet and returns the stake.

Line Movement And Market Terms

How numbers behave between posting and kickoff, and the vocabulary used to describe why they moved.

Line Movement And Market Terms.
Term	Definition
Opening line	The first price posted on a market.
Closing line	The final price available before the event begins, and the market's best estimate.
Closing line value	Whether your price was better than the closing price. The strongest short-run indicator of process quality.
Steam move	A rapid, coordinated move across multiple books caused by significant money.
Reverse line movement	A line moving against the side taking most of the tickets, usually indicating larger bets on the other side.
Key number	A margin that occurs disproportionately often, notably 3 and 7 in football.
Buying points	Paying extra juice to move a spread or total in your favour.
Middle	Holding both sides at different numbers such that a result between them wins both.
Hedge	A bet on the opposite side of a position you already hold, to lock in profit or reduce risk.
Arbitrage	Backing both sides at prices that guarantee profit regardless of outcome.
Look-ahead line	A price posted well before an event, typically a week or more in advance.
Sharp money	Wagers from bettors the book considers skilled, which are weighted more heavily in line setting.
Square	A recreational bettor, generally assumed to favour favourites, overs and popular teams.
Market maker	A book that sets prices independently and takes large positions, which other books follow.
Limits	The maximum a book will accept on a market, and a signal of how confident it is in the price.
Off the board	A market temporarily removed, usually because of unresolved news.
Circled game	A game with reduced limits, typically due to injury or weather uncertainty.
Consensus	The distribution of public wagers across a market, expressed as percentages.

Money And Staking

The vocabulary of bankroll and sizing, which determines outcomes more reliably than selection does.

Money And Staking.
Term	Definition
Bankroll	The total money set aside for betting, separate from everyday funds.
Unit	A standard stake expressed as a percentage of bankroll, typically 1% to 2%.
Flat betting	Staking the same amount on every play regardless of confidence.
Percentage betting	Staking a fixed percentage of the current bankroll, so stakes move with results.
Kelly criterion	A formula giving the growth-optimal stake for a known edge, usually applied fractionally.
Expected value	The average result of a bet if it were repeated indefinitely at the same price.
ROI	Profit divided by total amount staked, expressed as a percentage.
Variance	The dispersion of results around the expected value, and the reason long losing runs are normal.
Drawdown	The decline from a peak bankroll to a subsequent low point.
Risk of ruin	The probability of losing the bankroll entirely, driven mainly by stake size.
Chasing	Increasing stakes to recover losses, and the most common cause of destroyed bankrolls.
Stop-loss	A pre-set deficit at which betting stops for the day.
Sample size	The number of plays required before results carry information about skill.
Regression to the mean	The tendency of extreme results to be followed by more ordinary ones.

Handicapping Terms

Analytical vocabulary that recurs across sports, from ratings to the situational factors applied on top of them.

Handicapping Terms.
Term	Definition
Power rating	A numerical strength estimate for each team, from which a projected spread is derived.
Home field advantage	The points credited to the home team, roughly 1.5 to 2.5 in the NFL and shrinking across sports.
Pace	The number of possessions a team plays per game, and the foundation of basketball totals.
Efficiency	Points scored or allowed per possession, which separates quality from tempo.
Park factor	A ballpark's effect on scoring relative to an average venue.
Listed pitchers	A baseball bet condition voiding the wager if either named starter does not pitch.
Back-to-back	Games on consecutive days, most significant in basketball.
Short week	A football team playing on Thursday after a Sunday game.
Load management	Resting healthy players by policy rather than for injury.
Game script	How a game is expected to unfold, which drives usage and therefore props.
Garbage time	Late-game minutes with the result decided, which distort both pace and efficiency.
Projectability	How reliably a statistic predicts its own future values.
Split	A subset of results, such as home versus road, often quoted without regard to sample size.
Situational spot	A schedule or motivation circumstance applied as an adjustment to a projection.

Slang And Shorthand

Language you will encounter in betting communities, included so it can be recognised rather than adopted.

Slang And Shorthand.
Term	Definition
Chalk	The favourite.
Dog	The underdog.
Cover	A favourite winning by more than the spread, or an underdog losing by less.
Backdoor cover	A late score that changes the spread result without changing the winner.
Bad beat	A loss caused by a late, improbable event.
Lock	A supposedly certain bet. No such thing exists in a priced market.
Fade	To bet against a team, a bettor or the public.
Tail	To follow someone else's play.
Sweat	The experience of watching a bet you have money on.
Book it	Slang for placing the bet, from bookmaking.
Action	A bet, or a baseball bet condition where the wager stands regardless of the starting pitcher.
Bankroll killer	Any habit that produces ruin regardless of selection quality, chasing being the usual example.
Steam chaser	A bettor who follows line movement after it has already happened, buying the worse number.
Live dog	An underdog considered to have a genuine chance of winning outright.

Where To Go Next

Definitions are a starting point rather than an education. The terms that matter most have full treatments elsewhere on the site.

If you are new: start with the beginner's guide, then reading odds and implied probability.

If you want the maths: expected value, vig and juice and sample size.

If you want to stop losing: bankroll management and common mistakes, in that order.

If you want to get better prices: line shopping and closing line value.

If you want to handicap: power ratings, then the sport pages under picks.

Frequently Asked Questions

What does vig mean in sports betting?

The bookmaker's built-in margin, also called juice. It is why both sides of a market imply more than 100% combined probability, and why break-even at −110 is 52.4% rather than 50%.

What is the difference between a spread and a moneyline?

A moneyline bets on who wins outright. A spread applies a handicap to the favourite, so the bet is on the margin of victory rather than the result.

What does closing line value mean?

Whether the price you took was better than the final price before kickoff. It is the strongest available short-run indicator that a process is working, well before win-loss results become meaningful.

What is a push?

A tie between the result and the number — a game landing exactly on the spread or total. The bet voids and the stake is returned, which is why whole numbers are offered at all.

What does 'chalk' mean?

The favourite. Betting chalk means backing favourites, and a 'chalky' card is one made up largely of them.

Sports Betting Glossary

Odds And Prices

Bet Types

Line Movement And Market Terms

Money And Staking

Handicapping Terms

Slang And Shorthand

Where To Go Next

Frequently Asked Questions

Related Analysis

Beginner's Guide

How To Read Odds

Vig And Juice

Expected Value

Bankroll Management

Plain Language