CORTENOdds analysis means computing the probability implied by a price (1 / odds), removing the market margin and comparing it with historical data. It does not say that an outcome will happen. A sound reading weighs the time of the price, the margin, the data coverage and the sample size together.
Odds analysis means working out the probability a price implies and comparing it with historical data. It does not tell you that a result will happen. A sound reading looks at the time of the price, the market margin, the data coverage and the sample size together.
Implied probability
For decimal odds, the starting calculation is 1 / odds. Odds of 2.00 correspond to an implied probability of 50%; odds of 4.00 to 25%. This is not the “true probability”: the market margin is part of the number. Try these numbers in the free odds to probability calculator.
Remove the margin
If the 1-X-2 prices are 2.10 / 3.25 / 3.60, the implied probabilities are roughly 47.62% / 30.77% / 27.78%. The total is about 106.17%; the 6.17 points above 100% are the excess built into the prices. Basic normalisation rescales the three values to 100%; it does not produce the true probability of the outcome.
Try the three prices in the calculator.
Opening and closing
Opening and closing are two recorded moments in a particular dataset. Different sources may record different times. The difference between two prices does not, on its own, explain why the price moved or what the result will be. Read the opening vs closing odds guide for detail, and keep the sample size in mind when you look at past results.
Last updated: 4 November 2026 · Responsible: Cortenscore editorial team · Spotted an error? Report a correction. This page is for statistics education; it is not a prediction or betting advice.