Odds & Betting Glossary
Clear, plain-English definitions of the sports betting and odds API terms developers and bettors run into most.
Odds API
An odds API is a web service that delivers sports betting odds from one or more bookmakers in a structured, machine-readable format (usually JSON over REST or WebSocket), so developers can fetch and compare prices programmatically instead of scraping bookmaker websites.
Sports Betting API
A sports betting API is an interface that gives applications programmatic access to betting data (odds, events, markets, results and sometimes value/arbitrage signals) across one or more bookmakers, typically as JSON over REST and WebSocket.
Arbitrage Betting
Arbitrage betting (also called an "arb") refers to a price gap between bookmakers: the best available odds for every outcome of an event, taken from different bookmakers, imply a total probability under 100%.
Value Betting
A value bet is a price above a fair-odds estimate for the outcome, which means positive expected value (+EV) measured against that estimate. It says nothing certain about any single result, and it is only as reliable as the estimate behind it.
Moneyline
A moneyline bet is a wager on which side wins an event outright, with no point spread or handicap. The odds reflect each side's win probability: favourites pay less than the stake, underdogs pay more.
Asian Handicap
An Asian handicap is a betting market that gives one team a virtual head start or deficit (the handicap), which is applied to the final score to settle the bet. It removes the draw, leaving roughly two equally likely outcomes.
Implied Probability
Implied probability is the conversion of betting odds into a percentage chance, representing the likelihood of an outcome implied by the price. For decimal odds it is 1 ÷ decimal odds; the figures across all outcomes sum to more than 100% because of the bookmaker margin.
In-Play Betting
In-play betting (also called live betting) is placing wagers on an event after it has started, while it is still in progress. Bookmakers continuously recalculate odds in response to the unfolding action, so prices change second by second.