Guides
Understand what the odds really give back: factual, numbers-first explanations, with no betting tips.
What is the RTP of a sports bet?
The definition of Return To Player, how it is derived from the odds, a full worked example — and why the rate varies so much.
Read the guide →How to calculate a bookmaker's margin
The step-by-step method to measure the commission hidden in the odds, with two- and three-outcome examples.
Read the guide →Why accumulators are a gold mine for bookmakers
Odds multiply, but so do margins: the numbers behind the real price of accumulators and parlays.
Read the guide →Decimal, fractional, American odds: the three main formats
How to read each format, convert between them, and avoid comparison traps — with a conversion table.
Read the guide →Compare bookmakers by RTP rather than bonuses
A three-step method to judge an operator on its real price — its margin — rather than its marketing.
Read the guide →Sports betting terms explained
The words you come across without always understanding them — defined simply, with links to the detailed guides.
Read the guide →Work out the RTP yourself
Enter the odds of any bet and get its RTP instantly, no sign-up.
Open the calculator (browser version)