A bet where the odds offered by the bookmaker are higher than the true probability of the outcome, giving you a positive expected value over the long run.
A value bet exists when your estimate of the true probability of an outcome is higher than the probability implied by the bookmaker's odds. If you believe a team has a 40% chance of winning and the bookmaker is offering odds that imply only 30% — i.e., odds of 3.33 when fair odds would be 2.50 — that is a positive expected value bet.
Value betting is the only long-term profitable approach to sports betting. Every recreational bettor loses over time because they are betting into a market with a built-in margin. Value bettors systematically find situations where their model is more accurate than the bookmaker's model, and bet those discrepancies consistently over a large sample.
Expected Value (EV) = (Probability × Profit) − ((1 − Probability) × Stake). On a £10 bet at 3.0 odds where you estimate 40% true probability: EV = (0.40 × £20) − (0.60 × £10) = £8 − £6 = +£2. A +£2 EV on a £10 bet is a 20% return on investment — high by professional standards.
The challenge is accurately estimating true probabilities. Most successful value bettors use xG-based models to generate independent probability estimates, then compare those to bookmaker-implied probabilities after stripping the margin (using fair odds conversion).
Expected Value (EV)
The average outcome of a bet over a large number of repetitions — positive EV means the bet profits long-term; negative EV means it loses.
Implied Probability
The probability of an outcome embedded in bookmaker odds — calculated by dividing 1 by the decimal odds.
CLV (Closing Line Value)
The difference between the odds you backed and the odds at match kick-off — the best long-term predictor of whether your betting strategy has a genuine edge.
Kelly Criterion
A mathematical formula that calculates the optimal fraction of your bankroll to stake on a bet, maximising long-term growth given your estimated edge.
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