CLV (closing line value): what it is and why it matters more than the result
You can win with a bad bet and lose with a good one. CLV is a way of judging the decision without waiting for thousands of results.
What CLV is
Closing line value measures whether the price you got is better or worse than the closing price, the last one available before the event starts.
If you bet at 2.10 and the market closed at 1.95, you got a better price than the final one. You have positive CLV. If you bet at 1.80 and it closed at 1.95, the opposite happened.
Why the closing price is a good benchmark
The closing price has absorbed all available information: line-ups, injuries, money from informed bettors. In big, liquid markets it tends to be one of the best public estimates of the true probability. It is not perfect and does not call every result, but as a whole it is hard to beat.
So beating it consistently suggests you are pricing better than the market at the moment you bet.
Why it says more than short-term results
Results contain a lot of noise. At odds of 2.00, the standard deviation of your yield is about 10 points over 100 bets, as explained in how to tell if a tipster is profitable. You need thousands of bets before the result starts to say anything.
CLV is less noisy, because each bet gives a data point about the price whether you win or lose. With a few hundred bets it can already hint at a trend that results would take far longer to show.
How to calculate it
Simple version:
CLV = odds taken ÷ closing odds − 1
With 2.10 against 1.95: 2.10 ÷ 1.95 − 1 = +7.7%.
More precise version: the closing price includes a margin. The right approach is to remove it first, comparing with the fair price.
Suppose a two-outcome market closed at 1.95 / 1.95:
- Implied probabilities: 51.28% + 51.28% = 102.56%
- Probability without margin: 51.28 ÷ 102.56 = 50%
- Fair closing price: 2.00
- CLV: 2.10 ÷ 2.00 − 1 = +5%
This is the same logic used by the implied probability calculator. The difference between the two versions is the one between beating the price and having an estimated edge.
An example of how the result misleads
| Bet | Odds | Fair close | CLV | Result |
|---|---|---|---|---|
| A | 2.10 | 2.00 | +5.0% | Lost |
| B | 1.80 | 2.00 | −10.0% | Won |
Looking at the result, B was a win and A a miss. Looking at the price, A was the good decision. Repeating decisions like A should work in the long run if your closing prices are a good benchmark; repeating decisions like B should not.
Limitations
- It does not guarantee profit. CLV is a sign of an edge, not a promise.
- It works less well in illiquid markets. In small leagues or secondary markets, the closing price is a far less reliable benchmark.
- It depends on the benchmark. The usual choice is a low-margin bookmaker or a market average. The close of a high-margin bookmaker will tell you less.
- It needs a sample. A few bets are not enough. CLV does not escape chance either.
- Betting early has a cost. Many bookmakers limit stakes when a market opens or restrict winning accounts.
- A price can move for other reasons. News after your bet can hand you CLV by luck, without you having foreseen anything.
How to start measuring it
- Add a closing odds column to your records. The free Excel template is a good starting point.
- Note the price just before each event starts, always from the same benchmark.
- Work out the CLV of each bet and the average.
- Compare it with your yield once you have a sample.
BetTracker Pro does not currently calculate CLV automatically, because your bookmaker history does not include the closing price. What it does give you is the other side of the comparison, your real yield by sport, bookmaker and tipster: import your history and put it next to your record of closing prices.
Frequently asked questions
Does positive CLV mean I will make money?
No. It suggests you are getting good prices, but you can still lose for a long time, and it depends on the benchmark being reliable. Betting always carries risk.
Where can I find the closing price?
By noting it just before the event starts, or from odds comparison services with historical data. Always use the same benchmark so the data is comparable.
Does it work for parlays?
You can calculate it selection by selection, but it is less useful because the margin accumulates too. It is a more natural metric for single bets.