What is Expected Value?
Expected Value (EV) is the average amount you can expect to win or lose per bet over the long run. A positive EV means the bet is mathematically profitable; a negative EV means the house has the edge.
The Formula
Where:
P(win) = your estimated probability of winning
Profit = Stake × (Odds - 1)
P(lose) = 1 - P(win)
What is the Kelly Criterion?
The Kelly Criterion is a formula that determines the optimal bet size to maximize long-term bankroll growth. It tells you what percentage of your bankroll to wager based on your edge and the odds offered.
Where:
b = decimal odds - 1
p = probability of winning
q = probability of losing (1 - p)
Many professionals use "fractional Kelly" (e.g., half Kelly) to reduce variance while still capturing most of the edge.
Using EV with Stake.com
For Stake Originals like Crash, the odds are built into the game mechanics. At a 2x auto-cashout, the implied probability is 49.5% (due to 1% house edge). For Sportsbook bets, compare the offered odds to your estimated probability to find +EV opportunities.
Note: EV calculations depend on accurate probability estimates. In casino games, the house always has a mathematical edge. This tool is for educational purposes only.