# Betfair Trading Strategy Edge Calculator – Superb A/E Stat Explained!

By Marty •  Updated: 12/21/23 •  3 min read

At Betfair Trading Community we want you to be able to create Betfair Trading Strategies that give you an edge on the trading markets. So today we are going to show you a feature of the Betfair Trading Community software that makes this all possible!

One question that you should always be asking as a Betfair Trader is this:

Is my Betfair Trading Strategy Any Good? Or is it Just Lucky?

A great question but how can you find out the answer.

The Archie Score is great and one way of doing this (which coincidentally we also have available on the Horse Racing software) but is another way!

So what is it?

This new stat is called the A/E Index and here is an explanation of what it is:

The A/E index or ‘value index’ determines how often your selections are winning compared to how often they are ‘supposed’ to win according to the odds.

It produces a number to tell you the answer and using that information we can see if a Betfair trading strategy is worth trading or not.

So one important thing to know is that the break even figure is 1.0 and now we will explain why that matters.

In theory if you were backing a selection you would want a number above 1.0 (1.1 for example) to have found a strategy that is value. As you want horses or whatever you are backing to perform to their expected odds level or above.

If you were laying you would want a number below 1.0 (0.9 for example) to have found a strategy that is value. As you don’t want horses to perform to their expected odds level or above.

You can find this score after you run your strategy through the Betfair Trading Community software, just look for the Expected Value Box pictured below.

Here are the results from a Lay Strategy that I ran through the Horse Racing Software:

In this example strategy above the horse wins 0.91 times as ‘expected to’ 91/100. In other words these third favourites are 91% efficient.

Because these are LAY bets this is actually good as it means that the 0.09 inefficiency is in our favour.

If this was a BACK strategy, 0.91 would be a bad result as we would be taking odds that are 0.09 points worse than they should be.

Don’t worry to much if this seems complex, all that matters is this:

Summary:

1. An A/E value greater than 1.0 means that the horses outperformed what was expected of them based on the market better odds.
2. An A/E value lower than 1.0 means that the horses underperformed what was expected of them based on the market better odds.

Now go test your strategies and find out how good they are!