Odds and math
American odds
Also called moneyline odds, US odds
The +/− format used in the US, showing profit on a $100 stake or the stake needed to win $100.
Positive odds show the profit on a $100 bet: +250 wins $250. Negative odds show what must be risked to win $100: −150 risks $150. Even money is +100 or −100.
The format is unusual but has one practical advantage: the sign immediately tells you whether the market thinks something is more or less likely than a coin flip. Decimal odds, standard everywhere else, encode the same information as a multiplier on your total return.
Want the full version? Read the in-depth guide, with worked examples and the math.
See also
- Implied probability — The chance of an outcome as expressed by its odds, including the bookmaker's margin.
- Decimal odds — Odds expressed as the total return per unit staked, including the stake itself.