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Closing Line Value (CLV) is the percentage by which the line you bet at differed from the line at game time. Sustained positive CLV is the strongest predictor of long-term betting success — sharper than ROI in any short-term sample. If you bet the over at -110 and the same prop closed at -130, you got a better number than the market settled at — that’s positive CLV.

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How Line Gap calculates it

For each settled bet:
  1. We look up the closing line for the same prop on the same book (captured by our closing-line cron, which runs every 10 minutes during the tipoff window).
  2. Convert both the bet odds and the closing odds to de-vigged probabilities (so we’re comparing fair-value to fair-value, not vig-inflated numbers).
  3. CLV% = (fair_close_prob − bet_implied_prob) / bet_implied_prob × 100.
Positive = you beat the close. Negative = the market moved against your number.

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Where you’ll see it

Per-bet — /my-bets

Every settled bet shows its CLV in the dedicated column, color-coded green/red. Hover the column header for the formal definition.

Aggregate — /bankroll/clv

The CLV Dashboard surfaces:
  • Average CLV across all settled bets
  • Positive CLV rate — % of bets that beat the close
  • Best sportsbook — book where you’ve gotten the best numbers
  • Cumulative CLV trend — running average over time
  • By sportsbook / prop type / league — drill-downs to find your strengths

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When it works

CLV requires a closing line snapshot, which requires our closing-line cron to have captured the relevant prop. Right now that means:
  • Bets placed after closing-line capture launched (April 2026 onward)
  • In sports we capture closes for (NBA, NFL, NHL, UFC, NCAAB, NCAAF — MLB excluded by default)
  • In games where someone tracked a bet or the Discord bot posted a pick — closing-line capture is bets-driven to keep API costs predictable
Bets placed before then won’t have CLV. Old rows show ”—” rather than fake data.

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Why we say CLV is more important than ROI

In any short sample of bets, variance dominates. You can hit a hot streak on coin-flip lines and look profitable when you’re not, or you can get unlucky on +EV plays and look like you’re losing edge. CLV cuts through that. If you consistently beat the close, your bets are systematically priced better than the market — and over enough volume, that will convert to profit. ROI is the lagging indicator; CLV is the leading one.

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Honest caveats

  • Same-book CLV. We compare your bet’s odds to the closing odds at the same book you bet at. The “true” CLV would compare against the sharpest available closing line (often Pinnacle / Circa) — a refinement we may add later.
  • Straight bets only. Per-bet CLV currently populates for straight wagers. Parlays have well-defined CLV math but require a per-leg column we haven’t built. Tracked as a future enhancement.
  • You need volume. The CLV Dashboard waits for at least 5 settled CLV-tracked bets before showing trend charts (otherwise the data is too noisy to be useful).

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Coming soon

Best-line closing comparison

Not on near-term roadmapCompare your bet’s odds to the BEST available closing line across all books, not just the book you bet at. More accurate measure of market-relative skill.

Per-leg parlay CLV

Tracked as future enhancementSurface CLV for each leg of a parlay individually, not just the overall ticket. Requires schema work first.