Generate Parlay

Definitions

• American odds — e.g. +140 or −162 (positive = underdog; negative = favorite).
• Decimal odds — total return multiplier; 2.40× means $1 returns $2.40 if it hits.
• p̂imp (implied) — 1 / decimal.
• p̂fair (vig-removed) — normalize both sides so they sum to 100%.
• Edge — p̂fair − p̂imp. Positive suggests value.
• EV — expected return per $1: decimal × p̂fair − 1.
• Parlay hit probability — product of leg fair probabilities (assumes independence).
• Parlay EV — (Π decimal) × (Π p̂fair) − 1.