Implied probability, explained without the maths degree

7 November 2026 · 5 min read

Decimal odds of 2.00 mean one thing only: if this outcome happens, you get your stake back doubled. Everything else people read into it is interpretation.

From price to probability

Divide 1 by the price. That is the implied probability, margin included:

At 2.00 that is 50%. At 4.00 it is 25%. Simple — and almost useless on its own, because those numbers add up to more than 100%.

Removing the margin

Divide each implied probability by the total:

Now the three add up to exactly 100%, and you have the market's honest guess.

The uncomfortable consequence

A 50% outcome priced at 2.00 returns nothing over time. You need to be right more often than the price says, and the price already includes a cut. That is the whole game: you are not looking for likely outcomes, you are looking for mispriced ones.

This is why hit rate and profit are different things. A strategy can be right 74% of the time and still lose money, because the 26% of losses cost more than the wins pay.

A number worth remembering

To break even at price p, you need to win 1/p of the time. At 1.38 that is 72.5%. At 1.10 it is 90.9%. Write the break-even next to your hit rate before you feel good about a system.