FindMeBet

Sure bet calculator

Enter the best price you can get on each result, at whichever book offers it. The calculator splits your stake so every result returns the same amount, and tells you whether the prices actually combine into a sure bet.

What a sure bet actually is

Bookmakers do not agree with each other. They price the same match from different models, with different customers, and they move at different speeds. Most of the time the disagreement is small and every book still prices the market so that the house keeps a margin. Occasionally the disagreement is large enough that the best price on each result, taken from a different book each time, no longer leaves a margin at all.

That is a sure bet — also called an arbitrage, an arb, or a surebet. It is not a prediction, and it does not require you to be right about the match. You back every result, at the book pricing that result highest, in proportions that make all the returns equal.

The test: add up the implied probabilities

Decimal odds convert to an implied probability by taking the reciprocal. Odds of 2.00 imply 1 / 2.00 = 0.50, or 50%. Do that for every result and add them up:

Within one book that sum is essentially always above 1 — that excess is how the book makes money, and it is called the overround, the vig, or the juice. A typical soccer 1X2 market runs 4–7% over. Getting the sum below 1 means combining the highest price on each result across different books, which is the entire mechanic.

The calculator above shows this as Implied total. The Margin figure is 1 − Σ(1/odds) expressed as a percentage of the return: it is the fraction of your stake that comes back on top, if all the legs land.

The stake split

Once the prices qualify, the split is forced — there is exactly one way to divide a stake so that every result pays the same. For each result:

Each leg gets a share proportional to its implied probability. The short price gets most of the money; the long price gets a sliver. Multiply any leg's stake by its odds and you get the same return every time, which is the point — you no longer care which result happens.

A worked example

Three books, one 1X2 market, taking the best price on each result:

The implied probabilities sum to 0.9226, which is below 1, so the prices qualify. Two details are worth not glossing over, because they are where published examples usually quietly cheat:

• The legs do not return quite the same amount. They come out a cent apart, because a stake has to be a whole number of cents and the exact split is not. The figure that matters is always the smallest of them — 1,083.86 here, not the average and not the largest.
• The stakes add up to 1,000.01, not 1,000. Rounding each leg to the nearest cent can push the total a cent over what you asked for. The calculator reports what you would actually stake rather than the number you typed, and computes the margin from that.

Type these three prices into the calculator above and you will get exactly these figures. If an example on any site does not survive that test, the arithmetic behind it is decorative.

Round your stakes

A stake of 528.70 is a tell. Books watch for stake patterns that look machine-generated, and odd amounts to the cent across several accounts are one of the clearest. Rounding to the nearest 1, 5 or 10 costs a little precision — the legs no longer return exactly the same amount — and the honest figure is then the worst leg, which is what the calculator reports. Use the Round control above to see the effect.

What actually goes wrong

Every calculator on the internet stops at the arithmetic. The arithmetic is the easy part and it is never what costs you money. These are the failure modes, roughly in order of how often they bite:

1. The price moves before the second leg lands

You are placing two or three bets sequentially, at different sites, by hand. The first goes on at the price you saw. By the time the second is in, the book may have moved — often because of your first bet, if the market is thin. A sure bet that needed 4.65 on the draw and got 4.20 is not a sure bet any more; it is an unhedged position. This is the single most common way the theory and the outcome diverge, and it is why the order you place the legs in matters: put the leg most likely to move on first.

2. The stake gets cut

You ask for 528.70 and the book accepts 74. Limits are per-market and frequently far below the headline maximum on exactly the markets where mispricings appear — lower leagues, unusual props, anything the book is not confident pricing. A partially filled leg leaves you with a position that is neither the bet you wanted nor a clean hedge.

3. The bet is voided after the fact

Every book's terms include a palpable-error clause letting them void bets taken at an obviously wrong price. If your edge came from a genuine pricing mistake — a decimal in the wrong place, a market left open after team news — that is precisely the bet most likely to be voided. The other legs stay live. You are now holding a directional bet you never wanted. This is the direct reason to treat very large apparent edges with suspicion rather than excitement.

4. The "edge" was never real

This is the one nobody writes about, and in our own data it is the largest single category. When a scanner claims a double-digit edge, the overwhelmingly likely explanation is that it is comparing two things that are not the same market. Real cases we have had to fix:

• A book returning a first-quarter handicap under the field the scanner read as the full-game money line.
• A tennis doubles fixture fuzzy-matched onto the singles match — the two surnames in a singles tie are a subset of the four in the doubles pair, so naive name matching links them.
• A market that had been suspended, where the individual selections still reported themselves as open at placeholder prices.
• A feed shipping novelty markets as if they were fixtures — "Team vs Player", "matchday statistics" — which then match against real events.
• A silent sport-switch failure that served a soccer 1X2 market as a two-way money line, quietly turning the draw price into the away price.

The practical rule that falls out of this: an apparent edge above roughly 10% is far more likely to be a data problem than an opportunity. The median real edge is a bit over 1%. If your calculator is showing 30%, the first move is to open both books and read the market name.

5. The account gets limited

Sportsbooks are commercial businesses and are not obliged to keep taking your action. Consistently taking only the top price in the market is a recognisable pattern, and the usual consequence is not a ban but a stake limit low enough to make the account useless. This is a normal cost of the activity, not a scandal, and it is worth planning for rather than being surprised by.

Common questions

Do I need an account at every book?

You need one at each book you actually place a leg at, funded in advance. There is no time to deposit once you have found something — a price that survives a deposit and a KYC check was probably not much of a price.

Two-way or three-way?

The maths is identical for any number of results; the calculator takes as many legs as you add. Two-way markets (tennis, most totals, money lines) are easier to execute because there is one fewer leg to get filled. Three-way soccer markets throw up larger apparent edges more often, partly because the draw is the price books agree on least.

What about commission?

On an exchange, the effective price is lower than the displayed price by the commission rate. Enter the commission-adjusted odds rather than the headline ones, or the calculator will flatter the position.

Is this legal?

Placing bets is regulated differently in every jurisdiction, and in some it is prohibited outright. FindMeBet publishes odds data; it does not take bets, does not accept money for bets, and is not a bookmaker. Whether you may hold an account with any particular sportsbook is a question about your own jurisdiction and that book's licence, and it is yours to answer before you deposit anywhere.