WinRate AIFREE ANALYTICS TOOL
Expected value calculator for probability and odds.
Compare an independent probability estimate with decimal odds and calculate theoretical EV, break-even probability and the difference between estimates.
Educational calculation only. The result depends entirely on the probability estimate and does not guarantee a profit or recommend a transaction.
DEFINITIONS
Read every output separately
Break-even probability
The direct probability implied by decimal odds: 100 divided by the price.
Probability difference
Your estimate minus the direct market-implied probability, expressed in percentage points.
Expected value
The theoretical average net result if the same probability and price assumptions held across many comparable cases.
WORKED EXAMPLE
Example: 55% at decimal odds of 2.00
The price implies 50%. An independent 55% estimate is five percentage points higher. The theoretical EV is (0.55 × 2.00 − 1) × 100 = +10% of the illustrative stake. The event can still lose, and an inaccurate 55% estimate makes the output misleading.
LIMITATION
The formula cannot validate its own input
EV is conditional on probability quality. Check calibration, data timing, margin, market definition and settlement rules. Do not derive the independent estimate from the same unadjusted price and then treat the result as new evidence.