Part III: Business & Regulation · Gambling Mathematics & Probability

6. Expected Value (EV)

Foundational Probability

Expected value is the long-term average outcome of a wager calculated by multiplying each possible result by its probability of occurrence and summing these products. In casino games, virtually all bets have a negative expected value for the player (and positive EV for the casino), which is precisely what ensures casino profitability. For example, betting $1 on a single number in European roulette has an EV of ($35 x 1/37) + (-$1 x 36/37) = -$0.027, meaning the player loses an average of 2.7 cents per dollar wagered. Surveillance teams use EV calculations to evaluate whether player behavior indicates legitimate gambling or advantage play, as advantage players specifically seek bets with positive EV.

In practice

Formula: EV = (P(win) x Amount Won) - (P(lose) x Amount Lost). Positive EV (+EV) indicates a profitable bet; negative EV (-EV) indicates a losing bet. Advantage players are constantly searching for +EV opportunities.

One entry from the Casino Industry Glossary — 1,157 terms written for surveillance, compliance and operations professionals rather than for players. Definitions describe industry usage; where a term carries a regulatory meaning, verify against the instrument that governs your jurisdiction.