Moneyline, Point Spreads and Implied Probability Explained
A beginner-friendly guide to reading changing sports odds and understanding bookmaker margins and uncertainty.
Moneyline
Positive American odds describe the potential winnings on a 100-unit stake; negative odds typically describe the stake needed to win 100 units, excluding the original stake.
Point spreads
A -3.5 favorite usually needs to win by at least four to cover that selection. A +3.5 underdog can still cover when losing by three or fewer. Settlement rules vary by market.
Implied probability
Bookmaker margin means probabilities calculated from both sides of a market can add to more than 100%. Those probabilities are not guarantees or necessarily calibrated model probabilities.
Line changes
Availability, injuries, information and market demand can change prices. A screenshot may become stale; confirm current odds and terms with the provider.
Research responsibly
No pick is guaranteed, and gambling can cause harm. This guide is educational rather than betting advice. U.S. support: 1-800-GAMBLER.