Testing a price against "expected value betting" begins with one idea. Value betting means backing a price that is higher than the true chance of the outcome deserves. The idea is simple to state and hard to use: every price carries the book's margin, so a bet has value only when the bettor's own estimate of the probability beats the price by more than that margin. Expected value is the arithmetic that says whether a given bet clears the bar or falls short.
A clv betting strategy checks the work from the other side. Closing line value compares the price that a bettor actually took with the final price before the event starts. Beating the closing line again and again is the most reliable sign that a bettor's estimates are good, since the closing price gathers everything the market learned. Losing bets taken above the close are still good bets by that yardstick.
Expected value betting starts from one line of arithmetic. Multiply the chance of winning by what a win returns, subtract the chance of losing times the stake, and the result is the average gain or loss per bet over many repeats. A bet at decimal odds of 2.2 on an outcome that lands half the time shows a small positive number; the same price on a forty percent chance shows a loss, however good the bet may feel.
How to calculate expected value betting in practice: turn the decimal odds into an implied probability by dividing one by the price, then compare it with the bettor's own estimate. Odds of 2.5 imply forty percent. If the estimate is forty five percent, the expected value is positive by roughly an eighth of the stake. The whole method rests on that estimate, which is where most value bettors go wrong.
Hundreds, because small positive edges add up slowly and variance can hide them for a long time.
Only when the bettor's estimate of the chance beats the price by more than the margin the book builds into it.
An estimate made after looking at the odds tends to drift toward them, and the whole value method depends on that estimate being honest.
Dividing one by the decimal price gives the implied chance, so odds of 2.5 imply forty percent, and that figure is set against the bettor's own estimate.