Definition
What is expected value in sports betting?
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Definition
Expected value (EV) is the long-run average outcome of a bet, computed as (probability of winning × payout) − (probability of losing × stake). A positive-EV bet wins money on average over many repetitions; a negative-EV bet loses.
EV is the only metric that survives variance in the long run. A single +EV bet can lose; a portfolio of +EV bets, sized correctly, makes money over enough samples. The math is identical whether you're pricing a coin flip or an NBA winner — only the inputs differ. Operators compute EV against a model's fair price; the bet placed must have EV > 0 after vig.
How EV is computed
For a bet at decimal odds o with model-estimated probability p of winning:
EV = (p × (o − 1)) − ((1 − p) × 1)
= p × o − 1
If the result is positive, the bet has positive expected value. Glitch Edge’s cricket + NBA models output the probability p; the executor places only bets where the resulting EV exceeds the configured threshold.
Why EV alone isn’t enough
Knowing a bet is +EV doesn’t tell you how much to size. That’s where the Kelly criterion comes in — it converts edge into bet size as a fraction of bankroll.