A match rating is a percentage that shows how closely a bookmaker's back price matches an exchange's lay price for the same selection: back odds / lay odds x 100. In matched betting it ranks possible qualifying bets for the offers in betting promotions in Australia. With illustrative prices, $3.00 to back against $3.10 to lay rates 3.00 / 3.10 x 100 = 96.8%. A higher rating means a smaller gap, and usually a smaller cost to cover the bet.
Odds matchers sort bookmaker and exchange prices by this figure, as matched betting software explains, but the plain figure leaves out commission and treats every stake as cash.
How to work out a match rating
Divide the back price by the lay price and multiply by 100. With illustrative prices:
| Back | Lay | Working | Match rating |
|---|---|---|---|
| $3.00 | $3.10 | 3.00 / 3.10 x 100 | 96.8% |
| $3.20 | $3.10 | 3.20 / 3.10 x 100 | 103.2% |
Commission and the real rating
Commission comes off a winning lay, at a rate the exchange sets. For a cash stake, the share you keep after a balanced lay is back odds x (1 - commission) / (lay odds - commission). At $3.00 and $3.10:
| Commission (illustrative) | Working | Share kept | About what a $70 bet costs |
|---|---|---|---|
| 0% | 3.00 / 3.10 | 96.8% | $2.26 |
| 6% | 3.00 x 0.94 / 3.04 | 92.8% | $5.07 |
At 6%, the lay stake is 70 x 3.00 / (3.10 - 0.06) = $69.08, with a liability of 69.08 x 2.10 = $145.07. The pair loses $5.07 if the selection wins and 70 - 69.08 x 0.94 = $5.06 if it loses. That cost is the qualifying loss, and the back lay calculator works it for any stake and rate.
A rating over 100% is not always a profit. $3.20 against $3.10 rates 103.2%, but at 6% it keeps 3.20 x 0.94 / 3.04 = 98.9% of the stake, a small loss. The pair only gains when back odds x (1 - commission) is more than lay odds - commission, and then it is an arbitrage, which arbitrage betting in Australia covers.
Risk: Betting involves risk. An arbitrage only works if every bet is accepted at the price shown, and what each bookmaker's terms allow decides whether you can bet this way there. A bookmaker can limit stakes, void bets or close an account. See responsible gambling for limits and support.
Why ratings mislead on bonus bets
A stake-not-returned bonus bet is laid for its winnings only, so it keeps (back odds - 1) x (1 - commission) / (lay odds - commission) of its face value, which favours longer prices. At an illustrative 6%, $8.00 against $8.40 rates only 95.2% yet keeps 7.00 x 0.94 / 8.34 = 78.9% of a bonus bet, against 2.00 x 0.94 / 3.04 = 61.8% for the 96.8% pair. Sort bonus bets by the share kept, not the rating.
Risk: Betting involves risk. The two prices behind a rating are a snapshot, and a longer lay price puts more of your money at risk until the race or game settles. See responsible gambling for limits and support.
Comparing back and lay prices on the Terminal
On B337's Terminal, prices from 40+ bookmakers across racing and sports sit in their own columns wherever each prices the market, with Betfair's back and lay next to them, so both halves of a rating are on one screen. A free account opens a limited view of the Terminal with live odds, without the Betfair prices a rating needs. Prices are picked up on a repeating cycle, so confirm both in your accounts before you bet. Laying stays with you, because B337 does not bet on the exchange. Bookmaker and exchange names are trade marks of their owners. B337 is not affiliated with them.
Risk: Betting involves risk. A price on screen can trail the bookmaker's own. See responsible gambling for limits and support.