What a bookmaker’s margin actually is
Add up what a book’s three prices imply about the chances of a match and the total comes to more than certainty. The excess is the margin, and it is the only charge a bookmaker levies on every slip.
Explainers
This site publishes a column of percentages and expects a reader to act on it. These pages are the part that makes that reasonable: what the number is, what it is not, and the four or five other things that quietly cost money on a betting account.
Add up what a book’s three prices imply about the chances of a match and the total comes to more than certainty. The excess is the margin, and it is the only charge a bookmaker levies on every slip.
A margin is a number about a sample. Change the sample and the number changes, often by more than the gap between two books.
Most of the free bets in this market do not return the stake. That single condition takes roughly a third off the headline before any turnover requirement applies.
Four books in this market run no welcome offer at all and compete on an accumulator ladder instead. It is a real product, and it is applied to a slip the margin has already been taken out of.
A licensed operator pays winnings in full today. Anybody writing that winnings here have always been untaxed is wrong about every year a reader can remember.
The regulator publishes a list of licensed companies with their trading names, licence classes and dates. It does not publish licence numbers, which is why this site prints none.
Nobody sends a letter. You ask to stake fifty and the slip comes back accepted at five, and the terms that allowed it were agreed at sign-up.
Some books ship a real store listing, some ship a file from their own site, and at least one has a store listing that belongs to somebody else entirely.
One book in this market charges a percentage to withdraw. The rest do not, and the ceiling that actually catches a big win is set by the central bank rather than any of them.
If you read one, read the first. Everything on this site is built on the idea that a bookmaker charges a predictable amount on every slip and that the amount differs between books, and that page is where the arithmetic behind it lives.
If you have been betting for years and want the thing you probably do not know, read the one on why two bookmakers' margins usually cannot be compared. It is the reason this board grades its own figures rather than simply sorting them.