Price and probability are connected by a convention
For decimal odds d, the implied percentage is 100/d. This describes the arithmetic of the quote. It is not necessarily the true chance of the outcome, and a complete market may contain a margin. Keep the source and timing of the quote visible, especially when comparing numbers from different displays.
Three checks worth keeping
- Confirm that the input is decimal odds greater than one.
- Distinguish an implied percentage from an assessed probability.
- Avoid comparing unsynchronised quotes as if they were one market.
Put the question to work
The most uncertain part is often the probability estimate, not the arithmetic.
Use the price & probability explorer to organise the next step, then explore the worked example.
The tool is educational and supplies no live price or betting recommendation.
Continue your racing research
For a related racing resource, explore PTPTips horse racing ratings and form. Check the source for changing race information.
Terms used in this guide
- Decimal odds
- A price convention; the reciprocal implies a percentage but does not establish a true chance.
- Implied percentage
- 100 divided by decimal odds, using a quote greater than one.
- Overround
- The total implied percentage for a full mutually exclusive market minus 100 percentage points.
- Assessed probability
- A separate estimate of an outcome chance that needs its own justification.
- Boundary
- A maximum entered limit, which does not imply affordability or a target to spend.
- Timestamp
- The time associated with a quote or observation, including its timezone.
Related reading in the network
- decimal odds implied probability — Understand the arithmetic behind a price display and the limits of market percentages.
- set a gambling spending limit — Understand a fixed spending boundary and keep recreational records separate from income expectations.