Closing line value (CLV)
The difference between the odds you took and the final pre-event price, used as the most reliable indicator of long-run edge.
Closing line value (CLV) measures how your price compares with the last available price before the event starts. Liquid closing lines, particularly at sharp bookmakers or exchanges, incorporate nearly all available information and are hard to beat on average. A bettor who consistently gets better prices than the close tends to show a profit over a large enough sample.
Calculation with a no-vig close
Soccer, illustrative: you took a team at 2.10 on the draw no bet line. The two-way closing market was 1.95 / 1.95.
- Closing implied: 1/1.95 = 51.28% per side, 102.56% total.
- No-vig fair probability: 51.28/102.56 = 50.0%, fair odds 2.00.
- Your estimated edge: 2.10 × 0.50 minus 1 = +5.0%.
Raw CLV
A simpler version compares prices directly: 2.10/1.95 minus 1 = 7.7%. This overstates your edge because the closing price still contains vig. The no-vig version above is the better estimate.
Interpreting it
- CLV needs a smaller sample than profit and loss: a few hundred bets can show a clear CLV signal while results are still noisy.
- A thin closing market (lower leagues, obscure props) is a weaker benchmark.
- Bookmakers monitor CLV as well; consistently beating the close is a common reason accounts are limited.