Whether you won a bet is mostly luck. Whether you beat the closing number is mostly skill. CLV is the only feedback loop that tells you something useful about your process before a sample gets big enough to matter.
The closing line is the sharpest number a market produces. Every bit of information — injuries, weather, where the money went — is in it by the time the game starts. If you consistently bet numbers better than the close, you were early to something real. If you consistently bet worse ones, you were late, and the wins are borrowed.
This is the measurement that works on a small sample. A 55% win rate over 40 bets tells you almost nothing; the same 40 bets averaging positive CLV tells you the process is finding something. That gap matters most in exactly the situation where people quit or double down for the wrong reasons.
Track it per bet and average it over a season rather than reading any single number. One bet at +4% CLV is noise. Forty bets averaging +1.5% is a business.
A caveat that keeps people honest: beating the close at a soft book you can only bet $50 into is not the same as beating it at a book that takes real money. CLV measures whether you were right about the number, not whether you can act on being right.
Math, not advice. 21+ where legal. If gambling stops being entertainment, call 1-800-GAMBLER.