Guide
Expected value in football betting
Expected value answers a single question: if this exact bet could be placed a thousand times, what would the average outcome be? It is the number that separates a good bet from a bet that happened to win.
The formula
Expected value weighs the profit if the bet wins against the loss if it does not, using your own probability estimate rather than the market's.
EV = (p × (odds − 1) × stake) − ((1 − p) × stake)
Worked example
€10 at 2.10 with a model probability of 53%: EV = (0.53 × 1.10 × 10) − (0.47 × 10) = €5.83 − €4.70 = +€1.13 per bet.
The same €10 at 2.10 with a probability of 45%: EV = €4.95 − €5.50 = −€0.55. Identical price, opposite conclusion — the probability estimate is doing all the work.
EV is not win rate
A strategy backing 1.30 favourites can win 70% of its bets and still lose money. Another backing 3.50 shots can win 32% and be strongly profitable. Judge a record by return on investment against a stated sample size, never by strike rate alone.