What is Expected Value in Online Gambling?
Expected Value (EV) is the average amount a player can expect to win or lose per bet over time, calculated by multiplying the probability of each outcome by its payoff. For example, a bet with 55% win probability at even odds has a positive EV of +0.10 per unit wagered. Understanding EV helps players evaluate whether a bet offers long-term value or disadvantage.
How Expected Value Works
Expected Value quantifies the mathematical advantage or disadvantage in any wager. Positive EV (+EV) means the bet favours the player over time; negative EV (−EV) means the house holds an edge. For instance, a slot with 96% RTP has an EV of −4% per spin—the player loses 4 cents for every dollar wagered on average. Calculating EV requires knowing both the win probability and the payout ratio.
EV and Game Selection
Players comparing games should examine their EV, not just entertainment value. Blackjack with basic strategy offers approximately −0.5% EV, while roulette ranges from −2.7% to −5.4% depending on wheel type. Higher RTP games generally provide better EV, though volatility affects short-term results. No casino game offers positive EV for players—the house always retains a mathematical edge built into every wager.
Positive EV Bets | Negative EV Bets |
|---|---|
| Favour the player mathematically | Favour the house or opponent |
| Rare in licensed casinos | Standard in all casino games |
| Profitable over thousands of bets | Result in gradual losses long-term |
