Closing line value (CLV): what it is and how to measure it
Closing line value (CLV) compares the price you took with the last price before the start. How to measure it and what it does and does not say.
Closing line value, or CLV, compares the price you took with the closing line: the last price before the event starts. If you took a better price than the market closed at, you have positive CLV. If the price closed better than yours, your CLV is negative.
It answers a simple question: did you get a good price? Results take thousands of bets to settle down, but CLV gives you a reading on every bet, and its average settles far sooner.
Why the closing line matters
A market keeps changing until the start. News arrives, team sheets are named, and money from many bettors pushes prices up and down; the line movement guide explains why. By the start, the price has taken in nearly everything anyone knows about the game.
That makes the closing line, with its margin removed, the market's best estimate of each outcome's chance. It is not always right, but it is hard to beat consistently. Taking prices that are better than it, again and again, is a sign that your prices beat the market's final estimate.
Measuring CLV
Use decimal odds. Divide your price by the closing price and subtract 1:
CLV = your price ÷ closing price − 1
Say you took Team B at 2.20 and the market closed at 2.00:
- 2.20 ÷ 2.00 − 1 = +10%
- In probabilities: your price implied 1 ÷ 2.20 = 45.45%, while the close implied 1 ÷ 2.00 = 50.00%
Now the reverse. You took 1.90 and the price drifted out to 2.05 by the start:
- 1.90 ÷ 2.05 − 1 = −7.3%
The price got better after you took it, so you could have had more for the same outcome.
On spreads and totals the line can move as well as the price. Taking a team at −3 when it closes at −4.5, at a similar price, gives you 1.5 points of CLV. How much a point is worth depends on the sport and the number: in American football, many games end with a margin of exactly 3 or 7 points, so a line moving past those numbers is worth more than most others (point spreads explains why).
Compare against the fair close
The raw closing price still has the sportsbook's margin in it. A sharper measure compares your price with the fair closing price, with the margin removed (see fair odds).
Take the same Team B bet at 2.20. The two-way market closed at 1.85 on Team A and 2.00 on Team B:
- Implied: 1 ÷ 1.85 = 54.05% and 1 ÷ 2.00 = 50.00%, a total of 104.05%
- Fair probability of Team B: 50.00 ÷ 104.05 = 48.05%
- Fair closing price: 2.00 × 1.0405 = 2.081
- CLV against the fair close: 2.20 ÷ 2.081 − 1 = +5.7%
The raw figure said +10%; the margin accounts for the difference. The +5.7% is also an estimate of your expected value: 0.4805 × 2.20 − 1 = +5.7%. If the fair close is right, each unit staked on that price was worth about 1.057 units back on average.
Turn any closing market into fair prices with the calculator:
Read as American odds: −110
Read as American odds: −110
Margin 4.8%: the prices add up to 104.8%.
| Outcome | Implied | Fair chance | Fair price |
|---|---|---|---|
| Outcome 1 | 52.4% | 50.0% | +1002.001/1 |
| Outcome 2 | 52.4% | 50.0% | +1002.001/1 |
The fair price spreads the margin across the outcomes in proportion to their implied probabilities.
Tracking it over many bets
One bet's CLV says little. The average over many bets says a lot. Here are four bets, each compared with its fair closing price:
| Bet | Your price | Fair close | CLV |
|---|---|---|---|
| 1 | 2.20 | 2.081 | +5.7% |
| 2 | 1.95 | 1.90 | +2.6% |
| 3 | 2.50 | 2.60 | −3.8% |
| 4 | 1.80 | 1.75 | +2.9% |
| Average | +1.8% |
Bet 3 has negative CLV: its fair close of 2.60 was above the 2.50 taken, so a better price was there by the start. The other three beat the close. The average is worked from unrounded figures (1.84%), so it differs slightly from averaging the rounded rows. Win or lose, an average above zero over a long run says your prices were better than the market's final view.
What CLV does not tell you
- It is not a result. A bet with positive CLV can lose, and one with negative CLV can win. CLV measures the price, not the outcome.
- The close can be wrong. It is the market's best estimate, not the truth. In thin markets, such as some player props or lower leagues, fewer people bet and the closing price is a weaker yardstick.
- Small samples mislead. A handful of bets can show any average. Look at dozens or hundreds before reading much into it.
- Fees still count. On an exchange, compare after its commission or fees, because the listed price comes before them (see betting exchanges).
Finding the closing price
Note the closing price at the start or look it up afterwards. On OddsKeepr, once a game has started its page shows the best price and the fair price at the close, and its line movement shows how they got there. The fair price at close is the yardstick this guide uses. Comparing prices across sportsbooks before you bet means you take the best price available at that moment, whatever the close turns out to be; how to compare odds shows how.
Betting always carries a risk of losing money, so if you bet, set a limit you are comfortable with and check that the sportsbook is licensed where you are. If gambling stops feeling like entertainment, free and confidential help is listed for every country under where to get help.