Every betting line is just a probability in disguise. Converting odds to implied probability lets you compare prices across books, evaluate whether a market price is reasonable, and detect when the vig is hiding bad value.
Two simple conversions, depending on the odds format:
If you add the implied probabilities of both sides of a typical market, the total exceeds 100%. A standard -110/-110 line implies 52.4% + 52.4% = 104.8%. That extra 4.8% is the book's margin. To get the "fair" or no-vig probability, you remove that margin proportionally. ParlayPilot's EV engine does this automatically before estimating edge.
Parlay payouts are calculated by multiplying decimal odds, which is equivalent to multiplying probabilities. A 3-leg parlay of 50% legs has an implied chance of 0.5 × 0.5 × 0.5 = 12.5%. If the parlay pays less than 8x stake (decimal 8.0), the price is bad regardless of how confident you feel about each leg.
Every leg's odds are immediately converted to implied probability for risk-tier matching, correlation analysis, and EV calculation. Combined parlay probability is computed leg-by-leg with correlation adjustments — naive multiplication overestimates true parlay probability when legs are positively correlated.
ParlayPilot applies these concepts automatically — every pick is scored for edge, confidence, and stability before you see it.
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