Value betting is the habit that separates long-term winners from everyone else. You are not trying to pick winners. You are trying to back odds that pay more than the true chance of the outcome. Do that often enough and the math works in your favour over time.
This guide breaks down implied probability, expected value (EV) and line shopping in plain language, with a worked example in American odds. For the full set of how-to walkthroughs, see our betting guides hub.
Finding value means comparing prices across books. Start with the leading betting sites in Canada, or check the new sports betting sites that often price markets loosely.
What value betting actually means
A value bet exists when the odds offer a bigger payout than the real probability of the result. The sportsbook sets a price. You form your own estimate of the true chance. When your estimate says the outcome is more likely than the price implies, you have found value.
Here is the key idea. You will lose plenty of individual value bets. That is fine. Value is about the long run, not any single night. A coin paying +120 is a value bet even though it loses half the time.
Two skills make this work:
- Reading the price as a probability, not just a payout.
- Estimating the true chance with your own research, then comparing the two numbers.
If you are still learning to read prices, start with our betting odds explained guide first.
Implied probability: turning odds into a percentage
Every odds price hides a probability. To judge value, you have to convert the price into a percentage. That number is the implied probability.
For positive American odds the formula is simple:
- Implied probability = 100 / (odds + 100)
So +120 becomes 100 / 220 = about 45%. The sportsbook is effectively saying this outcome has a 45% chance.
For negative odds, the formula flips:
- Implied probability = odds / (odds + 100), using the number without the minus sign.
So -150 becomes 150 / 250 = 60%. Note that most private sportsbooks default to American odds, while provincial lottery products like Proline+ and PlayNow often default to decimal. Decimal makes this even easier: implied probability = 1 / decimal odds, so 2.50 = 40%.
Your estimate vs the market price
Once you can read implied probability, the value test is one comparison. Put your own estimate next to the implied number.
- Your estimated chance higher than implied = positive value.
- Your estimated chance lower than implied = no value, skip it.
Say you study a hockey matchup and conclude a team is around 50% to win the moneyline. The price is +120, which implies roughly 45%. Your 50% beats the market’s 45%, so the bet carries value. Read more on how those prices work in our moneyline betting guide.
The honesty of your estimate matters more than anything. A wrong estimate produces fake value. No outcome is ever a guaranteed win, so treat your numbers as a probability, not a certainty.
Worked example: spotting positive value
Let us run the hockey example all the way through with a $100 stake.
| Item | Value |
|---|---|
| Odds offered | +120 |
| Implied probability | 45.5% |
| Your estimated true chance | 50% |
| Profit if it wins | $120 |
| Loss if it loses | $100 |
Now apply the expected value (EV) idea. EV weighs each result by how often you think it happens:
- Win side: 50% of the time you gain $120 = +$60
- Lose side: 50% of the time you lose $100 = -$50
- Expected value = +$60 – $50 = +$10 per $100 bet
A positive EV means that, if your 50% estimate is sound, this bet earns about $10 on average for every $100 staked over many repeats. If your estimate had been 45% instead, EV would be roughly zero, and there would be no edge worth taking.
Why value, not picking winners, drives profit
New bettors chase winners. Sharp bettors chase value. The difference is everything.
You can win 60% of your bets and still lose money if you only back heavy favourites at terrible prices. You can win 45% of your bets and profit if every price beat its true probability. Long-term results come from the gap between your estimate and the price, repeated over hundreds of bets.
This is also why bankroll matters. Value plays out slowly, with losing streaks along the way, so you need staking that survives the swings. Our bankroll management guide covers flat staking and unit sizing built for exactly this.
The vig: the cost baked into every price
Before you celebrate any edge, account for the vig (also called juice or margin). The vig is the sportsbook’s built-in cut, and it is the reason the implied probabilities of both sides of a market add up to more than 100%.
Take a market priced -110 on each side of a point spread. Each side implies about 52.4%. Add them together and you get roughly 104.8%. That extra 4.8% is the vig. It is the hurdle every value bettor has to clear.
Two practical takeaways:
- A small edge can be eaten entirely by the vig, so your estimate must beat the price by a real margin, not a hair.
- Lower-vig markets leave more room for value. Comparing the same market in our point spread betting guide shows how the standard -110 pricing works.
Line shopping: capturing the best price
Line shopping is the simplest, most reliable edge available to any Canadian bettor. It means checking the same bet across multiple options and taking the best price before you commit.
The same hockey moneyline might be +120 in one place and +135 in another. Both could be value, but +135 pays more for the identical outcome and a larger edge over the implied probability. Over a season, those few extra cents per dollar compound into real money.
Single-event betting has been legal across Canada since August 2021, and prices vary between private sportsbooks and provincial lottery products (Proline+ in Ontario via OLG, Sport Select in Western Canada via WCLC, PlayNow via BCLC, Mise-o-jeu via Loto-Quebec). For a legality refresher, see is sports betting legal in Canada. The habit is the same everywhere: never take the first price you see.
A close cousin of line shopping is closing line value, covered below. When you regularly beat the price the market settles on, it is a strong sign your value judgments are sound.
Closing line value and related strategies
Closing line value (CLV) compares the price you took to the final price right before the event starts. If you bet +135 and the line closes at +115, you beat the closing line. Consistently beating the close is the clearest evidence you are finding genuine value, because the closing price tends to be the market’s sharpest estimate.
Value betting also connects to a few other approaches worth knowing:
- Arbitrage betting exploits price gaps between options to lock in a profit regardless of result.
- Parlay betting can magnify value, but it also multiplies the vig, so each leg must carry real value first.
- Picks and predictions from any source are only useful if you check whether the quoted odds still offer value before you bet.
Start small. Convert prices to implied probability, compare to your own honest estimate, shop for the best line, and track your CLV over time.
Value betting, arbitrage and matched betting
| Approach | Where the profit comes from | Variance | Effort |
|---|---|---|---|
| Value betting | Backing prices above their true odds | High over the short term | Ongoing research |
| Arbitrage | Covering every outcome across books | Very low per bet | Fast execution, account risk |
| Matched betting | Turning promotions into guaranteed value | Very low | Tracking the offer terms |
Removing the vig: working out fair odds
Every price a sportsbook posts includes its margin, so the two sides of a market always add up to more than 100% in implied probability. To judge real value you need to strip that margin out and find the fair odds underneath. This is called removing the vig, or devigging.
The method is simple. Take both sides of a two-way market, convert each price to its implied probability, then divide each one by the total. If a game is priced -110 on both sides, each implies 52.4%, totalling 104.8%. Divide 52.4 by 104.8 and you get 50%, the fair, no-vig probability.
Compare that fair number to your own estimate, or to the price at a sharp, low-margin book, and you have a clean read on whether a bet holds value. The no-vig line is the closest thing to the market’s honest opinion.
Frequently Asked Questions
Value betting means backing odds that pay more than the true chance of the outcome. You compare the price’s implied probability to your own honest estimate. When your estimate is higher, the bet has value, even if it loses sometimes.
Multiply your estimated win chance by the profit, then subtract your estimated loss chance times the stake. Example: a 50% chance to win 120 dollars versus a 50% chance to lose 100 dollars gives an expected value of plus 10 dollars per 100 dollar bet.
Implied probability is the odds price expressed as a percentage. For positive American odds use 100 divided by (odds plus 100). So plus 120 implies about 45 percent. For decimal odds, divide 1 by the decimal, so 2.50 equals 40 percent.
The vig is the sportsbook’s built-in margin, which is why both sides of a market add up to more than 100 percent. At minus 110 each side, the total is about 104.8 percent. Your estimated edge must beat the price by enough to clear that margin.
Closing line value, or CLV, compares the price you took to the final price before kickoff. If you bet plus 135 and the line closes at plus 115, you beat the close. Consistently beating the closing line suggests your value judgments are sound.
No. Value betting improves your odds over the long run, but no single bet is ever a sure thing. Results come from many bets where your price beat the true probability, and only if your estimates are accurate and your bankroll survives the swings.
It is the price with the sportsbook margin stripped out. Convert both sides to implied probability and divide each by the total to find the fair, no-vig number.
Yes. Positive expected value and value betting describe the same idea: backing odds that pay more than the true chance of the outcome.
Betting should be entertainment, not a way to make money. Set limits before you start, take breaks, and never bet to recover losses. If gambling stops being fun, free, confidential help is available: ConnexOntario 1-866-531-2600 (Ontario), BC Responsible Gambling 1-888-795-6111, or your province’s helpline.
19+ (18+ in AB/MB/QC) | Please play responsibly | Odds approximate at time of writing | ConnexOntario: 1-866-531-2600 (ON) – see your province’s helpline for resources elsewhere.