Three formats, one meaning
Decimal odds (2.50) are your total return per unit staked — the simplest format and our default. Fractional (6/4) is profit-to-stake. American (+150 / −200) shows profit per $100 or stake needed to win $100. Every format encodes the same implied probability: 1 divided by decimal odds. 2.50 implies 40%.
The margin is the bookmaker's fee
Add up the implied probabilities of all outcomes and you'll get more than 100% — the excess is the overround, the book's built-in edge. A tight football match priced at 104% is a fair-priced book; 110% is expensive. Comparing one market across several books before betting is the fastest way to systematically save money — it's why our sportsbook rankings weight odds quality.
Value beats winners
A profitable bettor isn't someone who picks winners — it's someone who bets when their estimate of a probability exceeds the odds' implied probability. Backing a 50% event at 2.20 loses half the time and profits long-term. Chasing 80% favourites at 1.10 wins constantly and bleeds money. Judge every bet by the price, not the result.
Bankroll rules that survive contact
Flat-stake 1–2% of a dedicated bankroll per bet. Never chase a loss with a bigger stake, never bet to 'make back' a bad day, and track everything — the spreadsheet is more honest than memory. Betting should be entertainment with an edge-hunting hobby attached, never income you rely on.