Rowdie: Mathematical football prediction and betting tips

Value Bet Theory

Many skilled punters consider value bet being the only possible way to be profitable in sports betting.

What is a Value bet?

Value bet is a difference between the real probability and the probability given by a bookmaker.

In the definition, there is one important thing to stress and that is the “real probability“. Real probability in football betting is not as easy to calculate as it is by flipping a coin. Real probability is just an opinion and your goal is to have a more accurate opinion than the bookmaker.

How to spot a value?

The Sports betting community at Rowdie is offering you 3 tools to spot a value bet.

1. Predictive models for football scores

After a long period of evolution the paid football predictions are finally live. Now you can use predicted probabilities and compare the outcome with odds of any bookmaker.

The goal of our prediction models is to calculate the probabilities of a given match using machine learning and well known statistical and mathematical methods without any manual input.

Make sure to pay attention to the league predictability. Since the predictive models are retrospectively verified, the league predictability is a crucial factor in our predictions.

We advise you to be very critical towards the predictions of the leagues with low predictability. Read the details of our theory of football predictions to find more about the math behind the science.

2. Calculate odds using the odds creator

We are also giving you a chance to create your own odds and use your own tool with our free football odds creator to spot the value bet. The odds creator is more time consuming, but the outcome is fully in your control.

3. Value bets based on the historical odds

In the list of value bets we are displaying the odds where we detected a value by processing thousands of historical odds data and market trends. Each of the value bet detected by the model has a stake. The stake is helping to manage the risk that the model would take in the bet. It is somewhere between the Kelly bet and the Markowitz theory.

The important thing here is that the value is detected independently from the predictive models described in point number 1.

The math behind the value bet

Let us roll a dice. The possible outcomes are the numbers 1,2,3,4,5 and 6. The chance of landing any of the mentioned numbers is ⅙, which is 16,6′ %. The odds for ⅙ in a fair odds environment would be 100/16.666 = 6.00.

Now try to imagine a bookmaker offering odds 6.50 for landing some of the numbers – for example the number 3, while pushing the odds of the remaining outcomes (1,2,4,5,6) down to 5.50.

If you see a case when this is happening you have found a value bet. The difference between the odds of a bookmaker and the odds you calculated is called a value bet. The difference (odds from the bookie minus my calculated odds) has to be a positive number. In this case 6.50 – 6.00 = 0.50.

Expected value calculation

From the difference we can now calculate the Expected value. Please use our simple value bet calculator to get the right numbers.

(Possible Net amount won in the bet x probability of winning) – (Possible amount lost in the bet x probability of losing)

If we bet £100 on the number 3, the formula would give us the following output:

((100 *6.5-100)*1/6)(100 *(11/6)) = 91.6 – 83.3 = 8.3%. This means that from each £100 we bet under the mentioned probability conditions, we can expect to gain £8.3.

Other tools to spot the value in sports betting

Math is a great tool that helps you to quantify the feeling of the value. To spot a value bet you have to know the sport, the league and the teams (yes plural) within the league. It won’t really help you to be focused on your favourite team + 3 other most serious competitors within one league. You should watch as many details as possible. Keep in mind that you are competing against big money making companies, employing thousands of people.

What might work to your advantage

You are not an employee

This might look like a silly argument but think again. A regular employee works 8 hours a day and his job is to bring decent results. Employees know how to bring just the right amount of results to make the employer happy. Most of the employees are not trying to kill themselves to make the job 110% accurate, when 80% is enough. Knowledge is power and you can make this power work for you.

Guess what the majority does

Have you ever heard the following statement before? “I will bet on Team A or Team B to support them.” This is indeed a complete nonsense, has nothing to do with the correct psychological approach to sports betting and leads to disappointment.

The extreme amount of stakes and bets on a top dog will push the odds down and very likely the remaining odds up. Knowing how bookmakers earn money and spotting what the crowds do is the key to your success. Try to identify the public madness around a team and compare the odds with reality. I am sure you will find a value there.

Value bet is defined as a difference between the real probability and the probability given by a bookmaker

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