Every bet is a question about the future. Will this team win? Will this player score? But there's a more important question that smart bettors ask: Is this bet profitable in the long run? Answering that requires understanding a concept called Expected Value, or EV.

Expected value is the average amount of money you can expect to win or lose on a bet if you were to make it an infinite number of times. It's a way to measure the long-term profitability of a wager, cutting through the randomness of a single event.

Think of it like this. A single coin flip is unpredictable. But if you flip a coin 1,000 times, you can be pretty sure you'll get heads about 500 times. EV applies this same long-term thinking to betting. It helps you see beyond the single win or loss to the underlying value of the bet itself.

To find the EV of a bet, you need two things: the probabilities of all possible outcomes and the potential profit or loss for each outcome. The basic formula looks like this:

Let’s break it down with a simple, non-sports example: a coin toss.

Imagine someone offers you a bet. If a fair coin lands on heads, you win $11. If it lands on tails, you lose your $10 stake. Is this a good bet?

Let's plug the numbers into the formula:

• Probability of Winning (Heads): 50% or 0.5
• Profit if you win: $11
• Probability of Losing (Tails): 50% or 0.5
• Stake (amount you lose): $10

The expected value is positive $0.50. This doesn't mean you will win 50 cents on any single flip. It means that if you took this bet over and over, you would average a profit of 50 cents per flip. It's a profitable bet in the long run.

Now let's apply this to a real sports bet. Suppose the Golden State Warriors are playing the Los Angeles Lakers. A sportsbook offers odds of +120 on the Lakers to win. You decide to bet $100.

Odds of +120 mean a $100 bet will win you $120 in profit. The tricky part is determining the probability. A sportsbook's odds imply a certain probability, but your goal is to determine if your own estimated probability is higher. Let's say, after your own analysis, you believe the Lakers have a 50% chance of winning.

Let's calculate the EV:

• Probability of Winning: 50% (0.5)
• Profit if you win: $120
• Probability of Losing: 50% (0.5)
• Stake: $100

This bet has a positive expected value of $10. Based on your probability assessment, this is a wager worth making. If your analysis suggested the Lakers only had a 40% chance to win, the EV would be negative (EV = (0.4 * $120) - (0.6 * $100) = $48 - $60 = -$12), and you should avoid the bet.

The key takeaway is that your success depends on how accurately you can estimate the true probability of an outcome compared to the probability implied by the odds. Finding discrepancies where you believe the probability of an event is higher than the odds suggest is the heart of value betting.

Ready to check your understanding?

Understanding expected value is the first step toward making smarter, more calculated betting decisions. It shifts the focus from hoping for a win to identifying long-term profitable opportunities.