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Sports betting glossary & guides

Plain-English explanations of the concepts that actually move the needle — expected value, closing line value, arbitrage, the vig, and how to find an edge.

+EV betting

+EV (positive expected value) betting means placing bets whose price is better than the true odd…

Closing line value (CLV)

Closing line value (CLV) measures whether you bet at a better price than the market's closing li…

Arbitrage betting

Arbitrage betting ("arbing" or a "sure bet") means backing every outcome of a market at differen…

The vig (juice)

The vig (also called juice or hold) is the margin a sportsbook builds into its odds. It's why th…

No-vig odds

No-vig odds are the fair odds you get after removing the sportsbook's margin (vig) from a market…

Implied probability

Implied probability is the win rate that a set of odds represents — the break-even percentage yo…

Decimal, American & fractional odds

Betting odds come in three formats — decimal, American (moneyline) and fractional — that all exp…

The Kelly criterion

The Kelly criterion is a formula for the bet size that maximizes long-run bankroll growth given …

Line shopping

Line shopping means comparing the odds across sportsbooks and betting at the best available pric…

Sharp vs soft books

Sharp books take large bets and set efficient, low-vig lines; soft books cater to recreational b…

The moneyline

A moneyline bet is the simplest wager in sports: you're just picking which team or player wins, …

Point spread betting

Point spread betting (or handicap betting) gives the underdog a head start and the favorite a de…

Over/under (totals) betting

Totals betting (over/under) is a wager on the combined score of both teams — you bet whether the…

Hedging a bet

Hedging means placing a bet on the opposite outcome of a wager you already have, to lock in a gu…

How sportsbooks make money

Sportsbooks make money mainly from the vig — the margin built into every price — plus by balanci…