A basic parlay calculation multiplies decimal odds and estimated probabilities. That shortcut depends on independence.
What independence means
Two outcomes are independent when learning that one occurred does not change the probability of the other. Bets across unrelated games may be closer to independent than multiple bets within the same game, although shared information can still matter.
A common correlation example
A quarterback passing over and that team scoring over may be positively correlated. If the passing over happens, the scoring outcome may become more likely. Multiplying the standalone probabilities can misstate the true joint probability.
Why same-game parlays need care
Sportsbooks often price same-game parlays using models that adjust for relationships among legs. A simple public calculator cannot recover that model from the displayed prices alone. That is why EVBet labels its combined probability as an independence-based estimate.
Use the calculator honestly
The parlay calculator is useful for payout conversion, break-even probability, and independent legs. Treat the EV result as incomplete whenever the selections influence one another.
EVBet provides educational calculations, not betting recommendations. A mathematical edge depends entirely on the accuracy of the probability entered.