How to calculate the odds of bookmakers

Bookmakers' odds indicate the probability that is assigned to the occurrence of that event in question. Calculating our own quotas is very important for analysis and obtaining long-term benefits, but how is it done? Let's analyze it!

Analyze all the factors surrounding the event

Whether in football, basketball, tennis, esports or any sport, the most important point is to sit down and calmly analyze all the factors that may surround the event. Any circumstance that can influence the result or performance of the players or participants, even if it seems minuscule, can lead to a change in the odds and probability.

Weather conditions, player's trips, schedules, state of the pitch, mood, motivation... Each sport has its peculiarities and should be analyzed thoroughly. Thus, we will be able to draw the most accurate probability.

Drawing our own probability

Once the event has been analyzed, we will have to draw our own probability. For example, we have been analyzing a Real Madrid - Barcelona match and we finished the analysis by giving 50% odds to the victory of the white team. What would be the quota?

Calculating the odds is very easy, you just have to divide 100% by the % probability that we have given. For example:

100% / 50% = 2.00

If for example we had given Real Madrid a probability of 55%, the odds would be:

100% / 55% = 1.81

What does this mean? That if our analysis is correct, and the victory of Real Madrid is paid at more than that quota, it would be a bet with value and that would give us benefit in the long term. The reason is simple: if the bookmaker's odds are higher, it would indicate a lower probability of Real Madrid winning the match, which would be wrong according to our analysis (as long as it is correct).

How to accurately calculate the odds of bookmakers

Once we have analyzed and calculated our quotas, it's time to compare with those of the houses. For this you will have to know how to calculate the odds of the bookmakers, something very simple.

We must remember that bookmakers apply their own profit margin on odds. That is, they are not 100% accurate to the probability, but in those odds there is included a small margin (ranging from 0 to 10% approximately) of ”commission" that the house takes on each bet.

Let's put an event with three odds to match winner (home - tie - away):

1,90 - 3.50 - 4,10

Now let's calculate the margin (payout) of the bookmaker in question. The first step will be to get the full benefit like this:

(1 / 1.90) + (1 / 3.50 ) + (1 / 4.10) = 0,52 + 0,28 + 0,24 = 1.04

The second step will be to get the payout or percentage of payments, so:

(1 / Benefit) x100 = (1 / 1.04) x100 = 0.9615 x100 = 96.15%

This means that the bookmaker, within its own probability, gives 96.15% to each result. The 3.85% difference up to 100 would be the commission. Once we have this clear, let's calculate the probability of those odds mentioned above in the example, thus taking out the percentages of bookmakers.

Local probability: (1 / 1.84) x 96.15 = 52.25%

Probability tie: (1 / 3.50) x 96.15 = 27.14%

Probability visitor (1 / 4.10) x 96.15 = 23.45%

The sum of the three probabilities is greater than 100% for the simple reason of the commission that the bookmaker applies to its odds, since otherwise the players or users would always win.

Published by:

Ines Ledo
Editor of the Innovate Change