How are the odds for sports betting created?

How are the odds for sports betting created?

Creating betting odds is a long and complicated process. Each of the bookmakers has sports analysts (odsmakers) who must have extensive knowledge about a given sports discipline, as well as knowledge of the principles of probability calculus, analytical thinking and statistics. This is necessary, because the result of their work should be such odds that will be both favorable for the bookmaker and attractive for players. This article was published thanks to the"" Betting Software Analysis.   

The task of the person developing the sports offer at the bookmaker is to determine the probability of each result occurring in a specific event. Currently, it is a man, not a machine, that decides what will be the course for a specific event.

Its primary task is to determine the percentage per bet. This is nothing more than an assessment of how many percent the team is likely to win. It can be specified on a scale from 0 to 1, where 0 means that the specific event will definitely not happen, and 1 means that the event will definitely occur. All that is in between is an assumption of what the chance of a given outcome is.

1 / course = probability

As a result, we know that the legal bookmaker  Fortuna gives 59% chances of Legia's victory  (1 / 1.70 = about 59%), 28% estimates the chance of a draw (1 / 3.60 = about 28%), and Jagielloni's victory is about 21 % (1 / 4.80). If a player believes that, for example, the victory of Legia is more realistic, then it pays to place a bet on this type.

Why is the sum of the odds in the example above not 100%, but more? Everything that will be over 100% means the margin on which bookmakers earn. It usually ranges from 5% to 15% - in this case the  bookmaker's margin  is 8%. How high the margin will be depends on the bookmaker himself, who takes into account e.g. the attractiveness of the match and the number of bets placed on a given match.

For the Real Madrid vs. FC Barcelona match, the margin will probably be higher, as they are one of the most popular teams in the world, so there will be more bets on this match than on any other. It is worth paying attention to the odds, because if we notice that they are lower than other bookmakers, it means that the bookmaker has set a higher margin.

It should also be remembered that if we decide to play at a legal bookmaker,  a tax of 12% is deducted from each amount staked  (in Poland this is the tax on gambling). For example, we want to play Fortuna for the victory of Legia in the match against Jagiellonia (odds 1.70) and for the victory of Górnik Zabrze against Pogoń Szczecin (odds 2.00). The rate of our coupon is EUR 100.

The total rate will then be: 1.70 x 2.00 = 3.40. The 12% tax from the amount of EUR 100, as it is easy to calculate, will be EUR 12 , therefore our rate is multiplied by EUR 88 (EUR 100 - EUR 12). 3.40 x 88 EUR = 299.20 EUR. This means that if we hit the correct results of these two matches, we will win almost EUR 300, i.e. we will triple our contribution.

The second way to calculate your winnings is also to subtract the tax amount from the total: 3.40 x 100 EUR = 340 EUR (excluding tax). 12% of 340 EUR gives us 40.80 EUR, so 340-40.80 = 299.20. The first variant is simpler and faster. An additional tax of 10% is also deducted in the case of a one-time win over EUR 2,280.


For the correct calculation of the bookmaker's odds, you will need the following formula:

Example: If Totolotek has determined that the Norwegians have an 80% chance of winning a gold medal, then according to the formula above, 1 / 0.80 = 1.25. In the bookmaker's offer for the victory of the Norwegians in the team competition, such a rate will be just 1.25. The operator decided that the Norwegian victory was very real. If the player believes that the chances of this team's winning are even greater (e.g. 90%), then it is worth investing more money on this type.

How does it work in practice? Fortune for the Ekstraklasa match between Legia Warszawa and Jagiellonia Białystok offered the following odds: 1.70 for the victory of Legia, 3.60 for a draw and 4.80 for the victory of the guests from Białystok. To check how percentage the bookmaker evaluates this match, it is enough to convert the formula to:


Odsmakers are responsible for determining the odds for betting events

The greater the chance of a given event occurring, the lower the bookmaker's odds on it

When placing bets, be aware of the 12% gaming tax, which is deducted from every amount wagered by the player

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