Understanding the difference between betting and laying is vital for anyone who wants to make a living from football trading.
Betfair is the biggest betting exchange and this article will use screenshots to help newcomers understand exactly what they need to know about how to lay a bet.
Backing and laying for profit is essential to become a successful football trader, so let's go through step-by-step exactly what laying on Betfair is and how this kind of bet works.
How to lay a bet
A lay bet allows a football trader to play the role traditionally taken by the bookmaker. This means you are effectively betting against an event happening, with another person taking the odds you agree for the bet.
For example - let's say you are interested in betting on the winner of the Premier League.
Back and lay betting explained
Arsenal are the current favourites to win the Premier League at the time of writing, with back odds of 2.48, meaning a bet of £10 would result in £14.80 profit if Arsenal did win the title.
When you place a back bet, you are betting on something to happen.
A lay bet is therefore the exact opposite of this - so you are betting on something NOT to happen.
Arsenal's lay odds are 2.52. In fraction terms, both back and lay bets are set around the 6/4 mark.
Back and lay meaning in betting
A lay bet against Arsenal is betting that another team - not Arsenal - will win the Premier League.
If Arsenal win the Premier League, your bet loses. If Arsenal do not win the league, your bet wins.
That, effectively, is back and lay bets explained - it really is that simple.
So in this scenario, you do not think that Arsenal will win the Premier League, so you want to bet against them.
Placing a lay bet
When placing a lay bet, there are two figures to keep in mind, both of which are shown on Betfair.
The first of these is payout - the amount of money you could win on your bet, including your stake - and the second is liability.
Liability is the opposite of payout - the figure shows how much you could lose on your lay bet.
Therefore, liability is the amount of risk you are taking on by placing a lay bet.In this example, a £10 stake lay on Arsenal winning the Premier League has a payout of £25.20.
The liability is set at £15.20. This means that for every £10 you want to bet against Arsenal winning the Premier League, you stand to lose £15.20 if they do actually win the title.
A £100 lay bet against Arsenal would mean liability of £152 if they were to win the league.
When placing a lay bet, your liability is always removed from your account balance as Betfair has to assume the worst case scenario - that you lose your bet.
You can therefore never risk losing more than the money you already have in a Betfair account.
Once the Premier League winner has been decided, if Arsenal have not won the title and your lay bet is a winner, your payout and liability will both be returned into your Betfair account balance.
You can keep track of your ongoing back and lay wagers on Betfair by clicking the My Bets button.
This screen shows you how much you stand to win on the back and lay bets you have placed via the Betfair exchange - meaning you can always keep track of exactly where your money is staked.
On the My Bets screen you can also see the other bets you have placed in Betfair's other areas away from the exchange.
Incidentally, the cash out function many bookmakers now offer as standard is effectively a lay bet against the back bet you have already placed to ensure you win your bet no matter what happens.
Backing and laying for profit
Backing and laying for profit is right at the heart of how to succeed as a football trader.
The best way to make big money from football trading is to back a bet when it is available at high odds, then lay the same bet when the price has come down.
For instance, Leicester City were available to win the Premier League at high odds at the start of the season, whereas their odds were much shorter as they closed in on the Premier League title.
Let's take a look at an example of how backing and laying for profit works in practice, using the Euro 2016 tournament.
As you can see above, the favourites for the title are the traditional powerhouses of European football, with Germany, France and Spain currently the shortest priced teams to win Euro 2016.
But it is down the list of countries that is particularly interesting to back and lay in betting - Iceland.
Iceland at Euro 2016
Iceland were one of the major surprises during qualifying, finishing in second place in Group A, which meant 2014 World Cup semi-finalists the Netherlands were knocked out.
Iceland were available at gigantic odds at the start of the long qualifying process, with many shrewd football traders placing back bets on the team to win the tournament.
As Iceland recorded a string of stunning results in qualifying, including wins home and away against the Netherlands, their odds to win Euro 2016 started to steadily drop.
They therefore became a fantastic back-to-lay opportunity, with many traders who backed Iceland earlier at odds of, for example 500/1, choosing to lay them at shorter odds to lock in a big profit.
Iceland drew Portugal, Hungary and Austria in Group F of Euro 2016, with the top two from the group going through to the next round, as well as the best third-placed team.
It was a test for them, but their fantastic success in qualifying showed how capable they had become at international level in recent years.
Greece's historic success at Euro 2004 proved that smaller countries can thrive at the European Championships and, even with the new reorganisation to a 24 team event, Iceland had a chance.
Before the tournament began, Iceland were priced on the Betfair exchange at 100 to win Euro 2016, meaning a £10 back bet on Iceland would have resulted in a profit of £990 should they have taken the title.
Once they qualified from Group F, their odds dropped substantially, meaning it was then possible to place a lay bet against Iceland, locking in a good amount of guaranteed profit.
After their win against England, the more their odds came down, providing another chance to guarantee a sizeable profit for traders who had placed back bets on them to win the title.
Guaranteeing your profits from football trading
Making guaranteed profit is the ultimate goal of the football trader and the best way to make cash.
There is always some level of risk involved in football trading, but by sticking to the fundamentals of backing and laying for profit it is possible to earn big sums of money on Betfair's exchange.
The most popular laying strategy in football is still "lay the draw".
Click for our complete guide to lay the draw trading.