An oddsmatcher is a table that compares bookmaker back odds against betting exchange lay odds across a large number of markets at once, then ranks them by how close the two prices sit. The closer they sit, the less the bet costs you to place. That is the whole idea. Everything else is presentation.
If you are new to the method itself, start with no risk matched betting explained and come back. This post assumes you know what backing and laying are, and picks up at the point where you need to choose a market.
The problem an oddsmatcher solves
To place a matched bet you need two prices on the same outcome. A back price at a bookmaker, where you are betting on something to happen, and a lay price at an exchange, where you are taking the other side.
Those two prices are never identical. The bookmaker builds a margin into its odds and the exchange has other users setting theirs, so the lay price is almost always a little higher than the back price. That gap is what the bet costs you. If you back at 3.00 and lay at 3.10, you lose a small amount whichever way the game goes, and that small amount is the price of admission for unlocking the free bet attached to the offer.
Doing this by hand means opening a bookmaker in one tab, an exchange in another, and comparing prices market by market until you find a pair that sit close together. That works. It is also slow enough that most people give up on it within a week. An oddsmatcher runs the same comparison across every market it covers in one pass, and sorts the results so the cheapest bets are at the top.
Match rating, the number that does the work
The headline figure on any oddsmatcher is the match rating. It is a percentage, and the formula is as simple as it looks.
match rating = (back odds ÷ lay odds) × 100
Back at 3.00, lay at 3.10, and your rating is 96.8%. Back at 5.00 against a lay price of 5.20 and you are at 96.2%. Higher is better, and the practical reading is that a rating in the high nineties means the two prices are close enough that the bet will cost you very little.
The number people quote as a rule of thumb is 95%. Above that, a qualifying bet is usually cheap enough to be worth placing for a decent free bet. Below it, you are often handing over more than the offer is likely to give back. Treat that as a guideline rather than a law, because what actually matters is the cash cost of the bet against the cash value of the offer, and a big offer can justify a worse match than a small one.
A 96% rating on a £10 qualifying bet is a very different proposition to a 96% rating on a £50 one. The percentage tells you how tight the match is. It does not tell you how many pounds leave your account, which is why every oddsmatcher shows a second column.
Qualifying loss, the number that matters
Qualifying loss is what the bet actually costs you in cash. It is the figure to look at when you are deciding whether an offer is worth the trouble, because it is the only one denominated in real money.
Here is a worked example at 2% exchange commission. Rates vary between exchanges, so use your own when you run the numbers for real.
£10 back bet at 3.00, lay odds 3.10, commission 2%.
Lay stake = (3.00 × 10) ÷ (3.10 − 0.02) = 30 ÷ 3.08 = £9.74. Liability at the exchange: £9.74 × 2.10 = £20.45.
If the team wins: +£20.00 at the bookmaker, −£20.45 at the exchange. Net −£0.45.
If the team loses: −£10.00 at the bookmaker, +£9.55 at the exchange after commission. Net −£0.45.
Qualifying loss: about 45p either way, 4.5% of the stake. Match rating 96.8%.
Same result whichever way it goes, which is the point. That 45p is the cost of triggering whatever the bookmaker is offering. If the offer is a £20 free bet, you are paying 45p for a shot at roughly £15. That is a trade most people would take.
The lay stake and liability above come from the standard lay stake formula. We have walked through it properly in matched betting calculators explained, and the matched betting calculator will do the arithmetic for you in a couple of seconds.
A 100% match is not a free bet
This catches people out, so it is worth being clear about. Even when the back and lay prices are identical, the bet still costs you money, because the exchange takes commission on your winnings when the lay side comes in.
Back £10 at 3.00 and lay at exactly 3.00 with 2% commission and you are still about 13p down whichever way it goes. A perfect match is cheap, not free. Ratings above 100% do exist, when a bookmaker prices a market better than the exchange, but they are rare, short lived, and often a sign that a price is about to move.
The other quiet detail is that the same rating costs more at longer odds. A 100% match at 3.00 costs about 1.3% of your stake. The same 100% match at 10.00 costs about 1.8%, because there is more liability sitting at the exchange for commission to bite on. Given two matches with the same rating, the shorter one is usually the cheaper bet.
The rating tells you how tight the match is. The qualifying loss tells you what it costs. Only one of those is money.
How to read an oddsmatcher table properly
The columns vary between tools, but the four worth your attention are always the same.
- Rating. Sort by it, but do not obey it blindly. A 99% match on a market with almost no liquidity is worse than a 96% match you can actually get your full stake on.
- Qualifying loss. The cash figure. Compare it against the value of the offer you are unlocking, not against other qualifying losses.
- Liquidity at the lay price. The exchange price is only real if somebody is offering enough money at it. If you need to lay £200 and there is £40 available, your effective lay price is worse than the one on screen and your rating quietly drops.
- Event time. Odds drift. A great match on a game three days out may be a poor one by the time you get round to placing it.
That last point separates people who make matched betting work from people who lose money at it. An oddsmatcher is a shortlist, not an instruction. Every figure in it is a snapshot of prices at the moment it refreshed, and both sides can move between then and your bet landing. Check the live prices at both ends before you commit, every time.
The most common way to turn a good match into a bad one is placing the back bet, wandering off, and laying ten minutes later at a price that has moved. Load the exchange market first, place the back bet, then lay immediately. Thirty seconds of care per bet is the entire skill.
Free bets change the sums
Everything above describes the qualifying bet, the one you place to trigger the offer. The free bet that follows uses the same table but a different calculation, because most free bets are stake not returned, meaning you keep the winnings and not the stake.
£20 stake-not-returned free bet at 5.00, lay odds 5.20, commission 2%.
Lay stake = (4.00 × 20) ÷ (5.20 − 0.02) = 80 ÷ 5.18 = £15.44. Liability: £15.44 × 4.20 = £64.87.
If the free bet wins: +£80.00 at the bookmaker, −£64.87 at the exchange. Net +£15.13.
If the free bet loses: £0 at the bookmaker, +£15.13 at the exchange after commission. Net +£15.13.
Locked in: about £15.13, roughly 76% of the free bet's face value. Match rating 96.2%.
The practical consequence is that qualifying bets and free bets want different odds. For the qualifying bet you want short odds, because the qualifying loss is smaller there. For a stake-not-returned free bet you want longer odds, because you keep a bigger share of the face value. Somewhere around 4.00 to 8.00 is the usual sweet spot for free bets, and most oddsmatchers let you filter to that range for exactly this reason.
Where the data comes from
An oddsmatcher is only as good as its two feeds. It needs bookmaker back prices and exchange lay prices for the same event, lined up correctly, and recent enough to be worth acting on.
Two things are worth checking on whatever tool you use. The first is which commission rate it assumes, since that feeds straight into the qualifying loss column and rates vary between exchanges. If yours charges more than the tool assumes, your real cost is higher than the figure on screen, and a 5% rate roughly doubles the cost of a perfect match compared to a 2% one. The second is how recent the prices are, because every oddsmatcher is showing you a snapshot rather than a live feed, and a table that looked good an hour ago may not be good now.
We are building our own, currently in beta for members at the Oddsmatcher.
The calculator side is free
Once you have picked a match, the lay stake, liability, and locked-in position are a calculator job. Ours handles qualifying bets, SNR and SR free bets, and risk-free offers. No sign-up, no ads.
Open the Matched Betting CalculatorWhen an oddsmatcher will not help you
Two situations, both worth knowing before you spend an evening on this.
The first is the summer. Matched betting leans hard on the football fixture list, and when the leagues stop the offers thin out and the matches get worse. We wrote about that in is matched betting dead, and the short version is that the table gets sparse for a few weeks every year. That is a fixture problem rather than a tool problem, and no oddsmatcher can conjure markets that are not being priced.
The second is account restriction. Bookmakers limit accounts that only ever take offers, and no oddsmatcher can find you a good match at a bookmaker that will no longer accept your stake. That is the structural reason a lot of people run casino offers alongside matched betting rather than instead of it, since the casino side has a different account lifecycle and needs no exchange at all.
Is any of this actually profitable
Yes, and it is worth being precise about why, because it is the same reasoning that underpins everything on this site. A matched bet is not a prediction. You are paying a known, small, calculated amount, the qualifying loss, to unlock a promotion worth more than that amount. Repeat that across enough offers and the arithmetic holds.
That is expected value, and if the term is new, the academy covers it properly. What it is not is a guaranteed outcome on any single bet. Prices move, offers get pulled mid-qualification, a lay bet gets partially matched and leaves you exposed on part of your stake. Those things happen. They are the reason to start small, check both prices immediately before placing, and keep a record of what you are doing.
FAQ
What is an oddsmatcher?
A tool that compares bookmaker back odds against betting exchange lay odds across many markets at once, and ranks them by how close the two prices are. It tells you which bet will cost you the least to place when you are unlocking a bookmaker offer.
What is a good match rating?
Anything above 95% is usually workable for a qualifying bet, and the high nineties are better. The rating alone is not the whole answer, because what matters is the qualifying loss in pounds set against the value of the offer you are unlocking.
What is qualifying loss?
The cash you lose placing the qualifying bet, once both sides of the bet and exchange commission are accounted for. Back £10 at 3.00 and lay at 3.10 with 2% commission and your qualifying loss is about 45p, whatever the result.
How is match rating calculated?
Back odds divided by lay odds, multiplied by 100. Backing at 3.00 against a lay price of 3.10 gives 96.8%. Higher means the two prices are closer and less value leaks out of the bet.
Can a match rating be over 100%?
Occasionally, when a bookmaker prices a market better than the exchange does. Those matches are rare and short lived, and a price that far out of line is often about to move, so check both sides before you place anything.
Do I need an oddsmatcher to do matched betting?
No. You can compare prices manually across two browser tabs and the maths is identical. It is just slow enough that most people stop doing it, which is the practical argument for the tool.
Is matched betting legal in the UK?
Yes. You are using publicly advertised promotions and placing ordinary bets, and gambling winnings are not taxed in the UK. Bookmakers are equally within their rights to restrict or close accounts that only ever take offers.