Matcher

Matcher is a bet calculator program which works out what your LAY stake should be to make sure you win the same amount of money either at the bookies if your BACK bet wins or at Betfair if your LAY bet wins.  Matcher is a must have tool.

Right click and Save-Target-As on this link Download Matcher Now

Qualifying bet and Stake Returned (SR) free bet

This is what Matcher looks like.  You enter your BACK stake, BACK Odds and LAY odds down the left hand side. The Stake Forfeit is how much of this BACK bet the bookie is going to keep. For your Qualifying bet and a Stake Returned bet this will be zero. Having entered these numbers you click the Calculate button and the program will show you what your LAY Stake should be on the left hand side near the bottom - in this case your LAY stake is £24.44.

So by BACKING £25 at the bookies and LAYing £24.44 at Betfair you will get £23.22 back no matter what happens in the event - see the £23.22 in the Back Returns box just above the Lay Stake.  The Lay Returns shows the same amount.
For your qualifying bet this is obviously a loss of £1.88 - you backed £25 and got £23.22 returned - but remember with the qualifying bet you're losing only a few pennies to gain many pounds with the free bet that you're now going to get.

For a Stake Retuned free bet this shows a profit of £23.22!

 

Stake Not Returned (SNR) free bet

For a SNR free bet you enter the amount of the free bet the bookie is going to keep into the Stake Forfeit box.  This is usually all of the free bet amount.
So for our example this is a £25 SNR free bet  - we're backing and laying at big odds to extract as much as possible out of the free bet.
Matcher tells us the LAY stake is £21.47 and the profit we'll make is £20.40 no matter what the outcome of the event.

 

 

Sports Arbitrage (Arb)

It is possible to find opportunities where the BACK odds are greater than the LAY odds - this is called an "Arb" which is short for arbitrage.  Finding and using arbs for your qualifier bets and free bets (and any other bets) can mean you never lose any money and it can increase your profits substantially. 
Arbitrage is used widely in the financial markets.  It is where you're able to buy something in one market (in our case Betfair) for less than you can sell it for in another market (in our case a Bookmaker). 

The example below shows an arb. The LAY odds are less than the BACK odds.
The outcome of placing a £25 BACK bet at the bookies and a £30.61 LAY bet at Betfair with these odds is a guaranteed return of £29.08 - a guaranteed profit of £4.08 no matter what the result of the event. Sporting arbitrage generates cash every time the LAY odds are lower than the BACK odds - and this happens a lot!
The Closeness% box goes green when you've got an arb.

IMPORTANT: Betfair (the exchange) charges commission on your winnings (bookies don't) so the difference in the BACK and LAY odds must be big enough to compensate for this.  See the Back Comm. and the Lay Comm. in the middle of the Matcher screen - these are percentage commissions.
Back Comm. = 0 means the bookie is charging 0% commission. 
Lay Comm. = 5 is the normal 5% Betfair commission.

Matcher is a must-have tool. 
Right click and Save-Target-As on this link Download Matcher Now

Play around with the figures to get comfortable with it - you'll be using it every time you Match Bet.

Check out

a) the effect of a SNR free bet versus a SR freebet
b) how by using bigger odds for the SNR free bet increases the amount of free money you can get from the free bet
c) what the difference between the BACK odds and LAY odds has to be to compensate for the 5% Betfair commission