Closing Line Value
The difference between the odds you took and the final odds when the market closed, used as a proxy for whether you are beating the market.
Definition
Closing Line Value measures how the price you bet compares with the closing line, the last odds available before the event starts. Because the closing line reflects all available information and the most money, it is the sharpest price the market produces; consistently getting better odds than the close (positive CLV) is widely regarded as the strongest available evidence of long-term skill, even before results are known. Negative CLV over many bets suggests you are picking worse prices than the market's final consensus.
Worked example
You bet Team A at 2.10 (implied 47.6%) and the line closes at 1.90 (implied 52.6%). You secured a better price than the market's final estimate, so you have positive CLV, a good sign regardless of whether this single bet wins.
Why it matters
Professionals track CLV as a faster, higher-signal performance metric than profit, which is noisy; learners use it to check whether apparent wins come from skill or short-term luck.