Expected Value in Betting
The single number that separates a good bet from a lucky one.
What EV actually measures
Expected value is the average result of a bet if it were repeated many times at the same price and the same true probability. It doesn't predict any single bet's outcome.
The formula
EV = (P x profit if won) - ((1 - P) x stake), where P is your estimated probability of winning. A positive result means the price on offer is, by your own estimate, better than the market's implied probability.
Why a losing bet can still have been correct
A positive-EV bet can still lose - that's variance, not a mistake. A good betting process is judged by whether decisions were positive-EV when made, not by any single result.
FAQ
How do I get a probability estimate?
From research, statistical models, or informed judgment - the EV Calculator does the math once you supply that number.
Is EV the same as edge?
Edge is usually a probability difference (estimate minus implied probability); EV converts that edge into an expected dollar amount given a stake.