What is CLV (closing line value)?

Closing line value (CLV) is the difference between the price you bet and the market's final price before the game starts. If your price is better than the close, you have positive CLV; if it's worse, negative CLV. It's how professionals judge betting skill: not by last week's record, but by whether you consistently get better prices than the market's final answer.

How it works

The closing line is the market's best guess

Right before a game starts, the line stops moving. That final number, the closing line, has absorbed every bet, every injury report and every sharp opinion in the market. It's the most informed estimate of the game available before it starts.

You bet the Over at −105. It closes at −120. You beat the close: positive CLV. The market ended up agreeing with you, and you got in at a better price.
You bet the Over at −120. It closes at −105. Negative CLV: the market moved against your bet, and you paid a premium.

The formula

To measure CLV precisely, compare probabilities, and take the vig out of the close first:

CLV = closing no-vig probability − implied probability of your price

Implied probability: for plus odds, 100 ÷ (odds + 100). For minus odds, odds ÷ (odds + 100), ignoring the minus sign.
No-vig probability: one side's implied probability divided by the sum of both sides' implied probabilities. This is the simplest way to remove the margin; other devig methods exist.

You can also express it as expected value against the close: your decimal odds × closing no-vig probability − 1.

A worked example

You bet a side at +105. It closes at −115, with the other side at −105.

Your price: 100 ÷ 205 = 48.78%.
The close on your side: 115 ÷ 215 = 53.49%. The other side: 105 ÷ 205 = 51.22%. Together they add to 104.71%; the extra 4.71% is the vig.
The fair close on your side: 53.49 ÷ 104.71 = 51.08%.
CLV: 51.08% − 48.78% = +2.30 percentage points.
As expected value: +105 is 2.05 in decimal odds, and 2.05 × 0.5108 − 1 = +4.7% against the close.

Why devig matters: bet −110 and watch it close −110 on both sides, and you matched the close but still paid the vig. Your price implies 52.38%, the fair close is 50%, so your CLV is −2.38 points.

Why it matters more than your record

Any bet can lose. Any weekend can go 1–6. Results over a small sample are mostly noise, which makes them a poor way to judge whether what you're doing works.

CLV settles the question faster. Bettors who consistently beat the closing line tend to come out ahead over the long run; it's one of the most widely cited findings in sports betting. If you're beating the close week after week, keep going, even through a cold stretch. If you're consistently behind the close, a hot streak is luck wearing a costume.

Wins and losses tell you what happened. CLV tells you whether you should expect it to keep happening. Chase the better number, not the better story.

How to calculate and use CLV

By hand:

Record the price you actually got, not the price you saw.
Record the close on both sides of the same line, taken just before the game starts, from a sharp market if you can.
Remove the vig with the No-Vig calculator, and convert your price with the Implied Probability calculator.
Subtract your implied probability from the fair close. For CLV as expected value, use the Expected Value calculator with the fair close as the probability. The calculators are free.
Judge over volume. CLV on one bet means little. Over 50–100 bets, it's the clearest signal you'll get.

On Unjuiced:

Your own bets. In My bets, Beat the close shows how often your price beat the closing line once graded bets have closing prices, and each bet's detail shows your price against the close. Comparing regularly tells you whether your process, not your luck, is good.
Your tails. When you tail a Sharp Intel pick, the sooner you bet after the sharp's move, the more of their CLV you capture. Tail late, and the line has often already moved to meet them. Sharp Intel is on Syndicate.
Sharp Money's calls. The Sharp Money report card grades its calls against the closing line: Pinnacle's price with the vig removed, else the average of three or more books, else Novig and ProphetX. Sharp Money's full feed is on Pro.

Mistakes to avoid

Comparing with the raw close. The closing price on your side includes the vig. Matching it is not break-even.
Using a different line. CLV only means something on the same line. If you bet −3 and the close is −3.5, you need the closing price for −3, not −3.5.
Using one soft book's close. A sharp market, or several books together, makes a better yardstick than a single book that's slow to move.
Judging on a handful of bets. A few bets of CLV, good or bad, tell you very little.
Measuring live bets the same way. The close is the last price before the game starts, so CLV is a pregame measure.
Treating CLV as a promise. Positive CLV is evidence about your prices, not proof that the next bet, or the next month, will win.

Questions

What is closing line value in sports betting?

Closing line value (CLV) is the difference between the price you bet and the market's final price before the game starts. Getting a better price than the close is positive CLV; getting a worse one is negative CLV.

How do you calculate CLV?

Convert your price to an implied probability, remove the vig from both sides of the closing line to get a fair probability, and subtract: CLV = fair closing probability − your implied probability. A +105 bet that closes −115 against −105 has about +2.3 points of CLV.