Note: This is an advanced matched betting topic. If you are new to matched betting, I suggest reading my free guide first.

You may have seen me describe matched betting in the past as a "zero-risk" side hustle.

This means that if done correctly, it is impossible to lose money.

However, there are certain strategies in matched betting where each bet does contain the possibility of a loss in the short term.

Think of it this way:

Imagine you have a coin that is weighted on the heads side, so that it lands on heads 60% of the time.

You bet a friend that you're going to flip coins for the entire day, and every time it lands heads, he pays you $1, and every time it lands tails, you pay him $1.

That's a good bet.

Over several thousand flips, you're practically guaranteed to win 60% of the time.

However, in the short term, it's possible you might find yourself at a loss.

For example, the first five flips might be tails.

Unlikely, but possible.

However, your mind should be at peace, because you know that your EV (Expected Value) is positive.

You know over a long enough time frame, the laws of probability will play out in your favour.

It's the same in matched betting.

As long as we know our bets are EV positive, it means we'll find ourselves in profit over the long term

How to calculate Expected Value

A quick note: You don't need to understand how EV is calculated to matched bet successfully. Simply use the pre-made calculators I recommend in my free guide and it will work out the EV for you. All you need to understand is, if EV positive, you bet. If EV is negative, you don't bet. This explanation below is just if you're a nerd like me who wants to understand the maths behind it!

EV is all about probabilities.

The probability of an outcome coming true is worked out by the following:

1 divided by the lay odds, then multiply by 100.

Example:

If the lay odds on New Zealand are 1.25, the chance of them winning is:

 1 / 1.25 = 0.8, then 0.8 x 100 = 80% chance.

That also means the odds of them not winning are 100% - 80% = 20% chance.

Let's say we're trying to work out EV for a multi-bet with 3 legs.

We can do this probability calculation for every outcome in our bet.

As an example, let's say our second leg is a bet on South Africa, their lay odds are 1.50.

The chance of them winning is, therefore:

1 / 1.50 = 0.667, then 0.667 x 100 = 66.7% chance.

And the odds of them not winning are then: 100% - 66.7% = 33.3%.

Now we want to work out the probability for both of those to happen, as we are placing a multi.

We would simply go odds for NZ to win (80%) multiplied by odds for South Africa to win (66.7%).

80% x 66.67% = 53.36%

In the same way, the odds of NZ winning, but South Africa not winning, would be 80% x 33.3% = 26.64%.

And then, we'll add in a third leg, and work out those probabilities too.

In the end, the probabilities for the different combinations of legs will look something like this for a typical 3 leg multi:

• Win Win Win 49%
• Win Win Lose $9%
• Win Lose Win 16%
• Lose Win Win 15%
• Lose Lose Win 5%
• Lose Win Lose 3%
• Win Lose Lose 3%
• Lose Lose Lose 1%

Then, we need to work out how much we win/lose on each outcome.

This is much easier, because if it's a standard multi-promo, there are only three outcomes:

• We win all 3 legs, and win the bet (usually ~$60 in winnings)
• We win 2 legs, meaning we lose the bet but get a bonus bet (usually ~$15 loss)
• We win less than 2 legs, meaning we lose everything ($50 loss).

With all that data, we can now work out the EV (you can also see this in action in my Multi EV Calculator):

• Win Win Win 49% x $60
• Win Win Lose $9% x -$15
• Win Lose Win 16% x -$15
• Lose Win Win 15% x -$15
• Lose Lose Win 5% x -$50
• Lose Win Lose 3% x -$50
• Win Lose Lose 3% x -$50
• Lose Lose Lose 1% x -$50

If you multiply all this out, you should get:

• 49% chance to win $60
• 40% chance to lose $15
• 11% chance to lose $50

Which will give you an EV (Expected Value) of $10.58.

This means if we place this multi-bet infinite times, we will win $10.58 per bet on average.

1,000 bets should equal ~$10,580 in profit.

1,000 bets might sound like a lot, but at 20-30 bets per day it goes quickly. This is exactly how I've made over $40,000 from matched betting.

Remember, if the odds are in your favour, you will always win in the long run.

Trust the odds. In the long run, the laws of probability can't be beaten.