Underlaying is a key part to being a successful matched bettor and is a way of maximising profit from your bets. This technique is considered advanced but is vital if you begin to take up each way arbing as the majority of your place bets will be underlayed.

When we use the matched betting calculator, it automatically works out the best lay stake to use for our bet. This will usually result in either an equal loss between bookmaker and exchange or a slight profit between the bookmaker and exchange if your selection is an arb (if the price at bookmaker is higher than the exchanges, this is described as an arb).

Here is an example of an arb on the calculator: Back Stake £50, Back Odds 8, Lay Odds 6.2, Lay Commission 2%.

Back Bet

Lay Bet

Adjust Lay

Required Lay £
Bookmaker Exchange Cashback Total
If Back Wins
If Lay Wins

As you can see we will make £13.46 on any result. However we can turn this small profit into a bigger profit by underlaying the selection while ensuring the bet is still risk free. All we need to do is slide the adjust stake bar on the calculator toward the left of the calculator to underlay the bet. We can then make a massive £84.65 if our selections wins. It must be noted that if you are fully underlaying a selection you will only make profit if the your selections wins. If it loses then you will not make any profit.

Another useful tip for underlaying is when you get stuck in a roll-over bonus. For this example we are using the standard back and lay technique we use for our normal qualifying bets. This time however we will be underlaying the selection slightly to manipulate the commission we pay at the exchange. Our stake is £50, our back and lay odds are both 4.0 (3/1) and our commission is 2%. Usually we would lose £0.75 if our selections wins or loses, however if we underlay it slightly we can risk an extra £0.25 if the bet loses but not lose a penny if the our selection wins.

When we are tied into a roll-over bonus, every qualifying loss we take eats into profit, underlaying low odds in this way can save some of our profit as our selections are more likely to win than lose.


Is the opposite of underlaying. This technique is best served to save any potential qualifying loses. By overlaying we will take a smaller qualifying loss if our selection loses. A prime example of this is when using the Bet365 4/1 offer. If we overlay our selection and it loses we get our full stake back at the exchange. If it wins however we will lose more, but we can deduct this loss from our potential profit as we hit the winner on the offer.

There are many other useful ways to use overlaying. The SportNation Free Bets for Goals offer is another prime example. So long as our selection has odds under or around 2.0 and is a close enough match we can minimise our qualifying loss if our selection loses. However if they win we can deduct any qualifying loss we took from overlaying out of the free bets.

Here’s a quick example assuming our Back Stake is £1,000 Back Odds 1.9, Lay Odds 1.94, Lay Commission 2% and we are fully overlaying. Please note we have included result without free bets taken into account to show the initial loses before free bet extraction.

Outcome SportNation Exchange Profit/Loss
Team 1 lose +£900 -£959.20 -£59.20
Team 1 win -£1000 +£1,000.02 +£0.02
Team 1 win (1 goal) 1 Free bet (£60) After extraction +£54.00 -£5.20
Team 1 win (2 goals) 2 Free bets (£120) After extraction +£108.00 +£48.80
Team 1 win (3 goals) 3 Free bets (£180) After extraction +£162.00 +£102.80
Team 1 win (4 goals) 4 Free bets (£240) After extraction +£216.00 +£156.80
Team 1 win (5 goals) 5 Free bets (£300) After extraction +£270.00 +£210.80

As we can see from the table above we will not risk a penny if our selection loses or draws. If our selection wins, and only scores 1 goal we will only lose –£5.20, which is a very small sum for the stake amount and potential profit. Further goals after this will ensure very profitable returns after free bet extraction.