Betting margin: what is it and how to calculate it
The margin of bookmakers is their guaranteed earnings, a certain percentage that bookmakers charge from each bet made. The margin size directly affects the value of the proposed coefficients: the lower it is, the more profitable the coefficient is for the betting lover. The bookmaker does not hide what margin he lays down, however, specific figures are not indicated on the sites, and therefore, to assess the effectiveness of the game in a single office, you need to learn how to calculate the margin yourself.
What does margin mean?
What is the margin in bets (from the French margin – difference, advantage) can be explained by the example of a regular coin. As we know, the probability of heads or tails is the same – 50 percent each. And if the bookmaker accepted bets on this event, then in fact he would have to give an equivalent coefficient of 2.00 for both outcomes.
However, this is not profitable for the bookmaker. Therefore, he includes his commission in the coefficient, allowing him to bet on equally probable events with a coefficient of not 2.00, but, say, 1.91, which corresponds to a margin of 4.5%. From two opposite bets of 100 conventional units, the bookmaker will return 191 into circulation and take 9 conventional units for himself.
Margin is a barrier that must be overcome to make a profit, and the height of this barrier varies depending on the office, the popularity of the event, the sport and individual lines. It is most convenient to calculate the margin as a percentage.
How to calculate the margin as a percentage
The two most common situations in order to calculate the margin are events with two and three options to choose from.
Calculation formula for outcomes with two options:
Margin = 1 – 1/(Probability 1 + Probability 2), where Probability 1 = 1/Coefficient 1, and Probability 2 = 1/Coefficient 2.
For example, let’s take one of the most popular sports for betting – tennis. Novak Djokovic and Juan Martin del Potro met in the final of the 2018 US Open. The bookmaker took bets on Djokovic’s victory with a coefficient of 1.45, on del Potro he gave 2.84.
Margin = 1 – 1/(1/1.45 + 1/2.84) = 4%.
Calculation formula for bets with three options:
Margin = 1 – 1/(Probability 1 + Probability 2 + Probability 3), where Probability 1 = 1/Coefficient 1, Probability 2 = 1/Coefficient 2, Probability 3 = 1/Coefficient 3.
Consider the 2020 Champions League soccer match between Liverpool and Atletico Madrid. The bookmaker estimated the victory of Atletico with a coefficient of 7.15, a draw with a quote of 4.05, the success of Liverpool could be played for 1.58. We calculate the margin based on the proposed coefficients:
Margin = 1 – 1/(1/7.15 + 1/4.05 + 1/1.58) = 1.93%.
The Champions League is one of the leading tournaments in the world in terms of betting volumes, so the bookmaker limited himself to such a low margin.
Tips for beginners about betting margin
Each bookmaker has its own tactics for attracting players, and the margin value is just one of the tools of interaction. The comfort of the game can be influenced by a variety of factors: the number of offers and sports, the convenience of depositing and withdrawing money, bonus promotions, betting limits, and so on.
In any case, it must be remembered that in the same office you can meet the main outcomes with a margin of 3% and in the same event, having delved into the painting (let’s say, into the statistics of corners), you will encounter a margin above 7%.
The margin value strongly depends on the popularity of the tournament and the sport in a particular office. Favorable odds for the Champions League are not a guarantee that the same bookmaker will make a generous offer for cricket or baseball. All offers need to be checked individually, choosing the right bookmaker for your style of play.
Using the margin calculation formula, you can find out where you can find profitable coefficients for yourself. The main thing is to treat the margin without fanaticism. When choosing a bookmaker, take into account a combination of factors, because you need to play responsibly and with pleasure.