The metric used by professionals
Closing Line Value (CLV) is the difference between the odds you bet on and the market's final (closing) odds just before the event starts.
It is considered by many professionals as the best indicator of real edge in the short and medium term, even better than ROI alone.
Why the closing odds are special
Betting markets, especially at bookmakers like Betfair or Pinnacle, are very efficient. As the match approaches, more money and information enter the market, making the closing odds the most accurate possible estimate of the true probability.
If you consistently get odds better than the closing odds, it means you are able to identify value before the market.
How to calculate CLV
CLV = (Odds bet / Closing odds − 1) × 100
Example:
- You bet on team A at odds of 2.20
- The closing odds were 1.90
CLV = (2.20 / 1.90 − 1) × 100 = +15.8%
You obtained a positive CLV of 15.8%. This means your bet had a lot of value compared to the final market.
Does a positive CLV guarantee profits?
Not in the short term. You can have a consistently positive CLV and still lose in the first 100-200 bets due to variance. But in the long term (500+ bets), a sustained positive CLV is one of the most reliable signs that you will have a positive ROI.
| Average CLV | Interpretation |
|---|---|
| > +5% | Excellent edge |
| +1% to +5% | Good edge |
| 0% to +1% | Marginal edge |
| < 0% | No edge, review methodology |
Limitations of CLV
- It only works well in liquid markets (major European football, Grand Slam tennis, NBA...)
- You need to save the closing odds, which is not always easy to obtain
- Bookmakers that limit accounts (Bet365, Bwin...) may not be good references; Pinnacle or Betfair are better benchmarks
CLV is more useful than ROI in short periods because it is not affected by result variance. It is a leading indicator, while ROI is a lagging indicator.
How to track CLV with Oddfolio
You can add CLV as a custom tag in Oddfolio or save it in the notes of each bet. In the future, Oddfolio will natively incorporate closing odds tracking.
Conclusion
If you want to know if you have a real edge without waiting for 1,000 bets, start recording CLV. It is the fastest traffic light to know if your methodology works.