Closing Line Value: How to Tell If You're Actually Winning
Why your bet history doesn't tell you what you think it does — and what does.
The problem with W/L records
A 60% record over 50 games might be variance. A 40% record over 50 games might also be variance. Sample sizes in sports betting are far smaller than people realize, and a true 55% bettor can easily go 22-28 over a 50-bet stretch and feel like they suck.
The fix: stop measuring outcomes. Start measuring prices.
What closing line value is
Closing line value (CLV) is the difference between the price you got and the price the market settled at right before kickoff. If you bet -3 (-110) on a Sunday morning and the line closed at -3.5 (-110), you got positive CLV — you took a worse number than the market eventually believed.
CLV is the only real-time signal that you're betting sharp. It correlates almost perfectly with long-term ROI.
How to track CLV
Every time you bet:
- Write down: market, side, price, stake, time of bet.
- Five minutes before kickoff: write down the closing price for the same market on the same book.
- Calculate: (your price implied probability) - (closing price implied probability). Positive numbers mean you got CLV.
Some platforms (Pikkit, Action 24/7) do this automatically. The DIY version is a Google Sheet — that's all most pros use.
What good CLV looks like
A long-term winning bettor averages +1% to +3% CLV per bet. If you're hitting +2% CLV consistently across 200+ bets, you'll be profitable long-term regardless of what your W/L looks like in any individual month.
If your CLV is -1% or worse, you can stop second-guessing the variance. You're not winning long-term. Either change your process or stop.
CLV across books
Caveat: closing line at FanDuel is sharper than closing line at most regional books. If you're tracking CLV against a soft book, you'll inflate your numbers. Track against the sharpest book that prices the market — usually FanDuel or Pinnacle if you can access it.
Bottom line
Your W/L is mostly luck over any period under a thousand bets. Your CLV is mostly signal over any period over fifty. Track CLV. Make decisions from it. Ignore everything else.