CLV = odd obtained ÷ closing odd − 1. An odd taken at 2.20 for a close at 2.00 gives +10%. The rigorous method compares the margin-free probabilities of the two prices rather than the raw odds, because the closing market's margin mechanically inflates the gap. A positive CLV describes a price taken above the final price, nothing more.
What is closing line value?
Closing line value, or CLV, measures the gap between the odd at which a bet was taken and the last odd offered before the start of the match.
Its interest rests on an empirical fact: the closing odd is the price that has incorporated the most information. Team news, last-minute injuries, staking volumes, successive adjustments by the operators — everything the market has learned ends up in the final price. Regularly taking prices above that final price indicates that you were buying before the information had been priced in.
What CLV is not: a measure of results. It is calculated without ever looking at the score of the match, which is both its strength and the source of every misunderstanding surrounding it.
The two calculation methods
The simple method compares odds; the rigorous method compares margin-free probabilities.
Simple CLV
CLV = odd obtained ÷ closing odd − 1
An odd of 2.20 for a close at 2.00 gives 2.20 ÷ 2.00 − 1 = +10%. Direct, readable, enough for rough tracking.
CLV compared in probabilities
The problem with the simple method: the closing odd contains a margin, and that margin drags it down. Comparing an odd obtained with a loaded price amounts to comparing two different things — the measured gap mixes the real quality of the price taken with the closing market's margin.
The rigorous method therefore removes the closing market's margin before comparison, following the approach described on margin-free odds, then compares the two prices once brought back to a common basis. The gap obtained is smaller — and more honest.
The order of magnitude matters: on a market with 4 points of margin, the simple CLV overstates the gap by roughly 2 points. Across series of bets, that difference is enough to turn slightly negative tracking into apparently positive tracking.
Calculate a CLV, simple and margin-adjusted
Enter the odd obtained, the closing odd and, if you know it, the closing market's margin in points.
The odds the bet was taken at.
The last odds offered before kick-off.
Leave 0 if the closing market margin is unknown.
Result
- Implied probability of the odds taken
- 45.45%
- Implied probability at closing
- 50.00%
- Simple CLV
- +10.00%
- Margin-adjusted CLV
- +10.00%
Warning:
CLV compares two prices. A positive CLV describes odds taken above the final price, not a secured profit.
Which closing odd should you use?
A CLV only makes sense if the two prices compared describe the same bet. Four requirements, all of them indispensable.
The same market and the same line. A −1.5 handicap and a −1 handicap are two different bets. Comparing one with the other produces a meaningless figure.
The same settlement rules. Treatment of extra time, abandoned matches, refunds: two operators can offer the same apparent market with different rules.
An identified and constant source. Comparing an odd taken with one operator against another operator's close mostly measures the gap between two operators. If the closing source changes from one bet to the next, the series is no longer interpretable.
A reading close to kickoff. "Close" means last available price. A reading taken two hours earlier is not a close: it is an intermediate price, and odds movements show that the final hours often concentrate the most significant adjustments.
Is the closing odd always right?
No. It is the best-informed price available, not an exact price.
A closing market is still a market: it contains a margin, depends on the liquidity available and can be collectively wrong. On lightly followed competitions, secondary markets or sports with thin coverage, the close can be as imprecise as an opening price on a major match.
Treating the close as an absolute benchmark leads to a circular error: measuring your performance against a price assumed to be perfect, then concluding that beating that price proves a skill. The reasoning only holds if the close is genuinely well calibrated — something that is verified market by market, not postulated.
Does a positive CLV guarantee a profit?
No, and this page deliberately parts company with the content that presents CLV as near-automatic proof of profitability.
Three reasons, independent of one another.
CLV does not look at results. A series of bets with positive CLV can perfectly well end in a loss: a price gap makes no bet any more certain.
CLV does not account for real costs. Commissions, staking limits, restricted accounts, stakes not executed at the displayed price: all of that eats into a theoretical edge without ever appearing in the calculation.
A measured CLV can be an artefact. Prices compared across different sources, margin ignored, closing readings taken too early, selection of which bets are kept in the tracking: each of these flaws produces a positive CLV without any edge existing.
Key point. CLV is a price indicator, available faster than a measure of profitability because it does not depend on the variance of results. It is not a measure of profitability for all that, and a positive CLV excuses no caution whatsoever.
What OddScore does
OddScore tracks how the odds of several bookmakers evolve until kickoff and makes the path travelled by the price visible. It is that trajectory — opening price, adjustments, final price — that gives context to a closing gap.
The platform does not track a user's bets and does not calculate a personal CLV: it documents prices, not positions. The calculator above works from your own figures, with no account and no registration.
The three levels. CLV shows the gap between a price taken and the final price; it allows you to estimate the quality of the entry point across a long enough series; it does not allow you to conclude anything about profitability, either on a bet or on a series.
Dig into the market
Odds movements are only part of the story. Here are the next topics to read.
Odds and probability: the complete guide
The full journey, from the displayed odd to the closing line.
Read the guideOdds movements: understanding the market
What happens between the opening price and the final price.
Read the guideValue bet: what the gap really measures
The other possible comparison, which requires an independent estimate.
Understand the valueMargin-free odds: the proportional method
The indispensable step for comparing two prices rigorously.
Remove the marginFrequently asked questions
What is closing line value?
It is the gap between the odd at which a bet was taken and the last odd offered before the start of the match. It measures the quality of the price obtained, not the result of the bet.
How do you calculate CLV?
The simple method divides the odd obtained by the closing odd, then subtracts 1. An odd of 2.20 against a close of 2.00 gives +10%.
Why compare probabilities rather than odds?
Because the closing odd contains a margin. Comparing two raw odds mixes the real price gap with the closing market's margin, which overstates the CLV.
Which closing odd should you use?
The last odd of the same market, the same line and the same settlement rules, recorded as close as possible to the start of the match, from an identified and constant source.
Is the closing line always right?
No. It is the best-informed price available, but it remains a market price: it contains a margin, depends on liquidity and can be wrong.
Does a positive CLV guarantee a profit?
No. It indicates that the price obtained was above the final price. It says nothing about the result of the bet concerned, nor about the profitability of a series of bets.
Why track CLV rather than your winnings?
Because the winnings from a small number of bets are dominated by variance. CLV gives faster feedback on the quality of the prices obtained, without being a measure of profitability for all that.
Sources & methodology
This page draws on the literature devoted to the efficiency of betting markets and to the informational content of the closing line, on the usual margin-removal methods, and on the odds-tracking methodology developed by OddScore.
- Compare the odd obtained with the closing odd of the same market, the same line and the same rules.
- Calculate the simple CLV (odd obtained ÷ closing odd − 1).
- Recalculate the gap after removing the margin declared on the closing market, a more rigorous method because it neutralises the load built into the final price.
- Present the result as a price indicator, never as a measure of profitability.