Lesson
Closing Line Value
Before you know if a bet won, you can already know something useful about it: whether you got a better number than the market eventually settled on.
Quick answer
Closing line value (CLV) measures whether the price you bet at was better than the price the market closed at right before the game started. Consistently beating the close is one of the earliest honest signals that a betting process has a real edge.
The closing line is the market's final answer
Prices move constantly between when a line opens and when the game actually starts, as new information shows up and money comes in on both sides. The number right before first pitch, the closing line, reflects about as much collective information as the market is ever going to have on that game.
What closing line value actually means
Closing line value, usually just called CLV, is whether the price you bet at was better than where the line ended up closing. Bet a team at +142 and it closes at +120? You beat the close. That's positive CLV, you got a better number than the market eventually agreed was fair.
Positive CLV example
| You bet at | +142 |
| Line closed at | +120 |
| Result | Positive CLV |
The market moved toward your number after you bet it. That's a sign you saw something early that the rest of the market caught up to later.
Why it matters before the game is even played
A win/loss record needs a big sample before it means much. A coin flip can go 15-5 over 20 tries and mean nothing. CLV shows up bet by bet, and consistently beating the close is a real early signal that whatever process is finding these bets is actually finding something, well before the results catch up to prove it one way or the other.
You can win with bad CLV, and lose with good CLV
Any single bet can go either way regardless of the price. A team can be a legitimate underdog and still win. What CLV tells you isn't whether one bet hits, it's whether the process behind it is systematically getting good numbers. A model that consistently beats the close but runs cold for a few weeks isn't broken. A model with poor CLV that's winning anyway is probably just running hot, and that won't last.
How we use it
Every released position on this site records the release price, the closing price, and the CLV, permanently, win or lose. It's on the results page right alongside net units and ROI, because it's one of the fastest honest checks on whether the model is actually doing its job.