What is Closing Line Value (CLV)? The Complete 2026 Explainer

Updated September 29, 2026 · 8 min read

Closing Line Value (CLV) compares the odds accepted on a sportsbook bet with a defined closing price for the same market. It can help evaluate price quality across a sample, but cannot by itself establish a profitable strategy.

This explainer covers the calculation, the choice of closing reference, and the data quality needed to interpret a result. Read the methodology for definitions and limits.

Use the CLV calculator to follow the entry-versus-close comparison described below.

The Definition: What is Closing Line Value?

Closing Line Value measures the difference between the odds you bet at and the odds available on the same market at close (just before the event starts).

A closing line is a later market reference, not a known true probability. Its usefulness depends on market match, liquidity, timestamp, rules, and data quality.

Repeatedly obtaining a better entry price than a reliable close can be evidence of price discipline. It does not identify why the price moved or prove that a probability model is calibrated.

How to Calculate CLV

CLV is expressed as a percentage, measuring how much better your odds were relative to closing:

CLV % = (Your Decimal Odds / Closing Decimal Odds − 1) × 100

Example: You bet a team at +120 American odds (decimal: 2.20). The closing line is +100 (decimal: 2.00).

CLV % = (2.20 / 2.00 − 1) × 100 = (1.10 − 1) × 100 = +10%

In this illustration, the entry decimal odds are 10% higher than the quoted close. That is a price comparison, not a 10% expected return. Its meaning depends on the closing source and whether vig has been removed.

Converting American Odds to Decimal

CLV calculations require decimal odds. Here’s how to convert:

Positive American (e.g. +150): Decimal = (American / 100) + 1 = 2.50 Negative American (e.g. -110): Decimal = (100 / |American|) + 1 = 1.909

How to Interpret CLV

There is no universal CLV threshold that proves an edge. Compare like markets, record the source and observation time, use a no-vig calculation when both sides are available, and inspect the distribution across a meaningful sample. A positive average can coexist with negative realized ROI.

Why CLV Is More Predictive Than Win Rate or ROI

Win rate and ROI can swing substantially in small samples. CLV adds a price-based observation for each matched bet, but the close is an imperfect benchmark and observations may not be independent.

Review CLV alongside realized ROI, bet count, market mix, and missing closing references. A disagreement between CLV and ROI deserves investigation; neither metric alone explains whether the difference is luck, model error, or data quality.

Choosing a Closing Reference

Different sportsbooks and market composites may close at different prices. Document the source, time, side, line, and settlement rules, then keep that definition consistent when comparing bets. A restriction by a sportsbook is not proof that a CLV calculation or strategy is valid.

How to Track CLV With evrai

For sportsbook bets with a matched closing reference, Evrai can calculate CLV from the entry price and the documented close. The record needs:

The odds you got at bet placement (American or decimal)
A sourced and timestamped closing price for the same market, side, line, and settlement rules, when available

Where a valid close exists, Evrai can calculate CLV. Review it alongside realized ROI and the count of comparable bets with closing coverage. Comparing periods describes how recorded prices changed; a 30-day difference does not prove that an edge improved or declined. Kalshi and Polymarket fair-value comparisons use a separate measure that requires an independent estimate available at fill time.

Check the current plans for CLV access.

Frequently Asked Questions About CLV

Does CLV work for all sports?

CLV can compare matched prices in many sports, but its usefulness varies with market liquidity, the quality and timing of the closing reference, and contract rules.

What closing line should I use?

Use a documented reference for the same market, side, and rules, observed at a consistent time. Compare sources and account for vig; no single book is automatically a valid benchmark for every market.

Can I have positive CLV but still lose money?

Yes. CLV describes the entry price relative to a later reference, not the result. Positive CLV does not guarantee profitability, and both CLV and ROI need enough comparable observations to interpret.

Does CLV apply to player props?

Yes, when the player, line, side, and settlement rules match. Lower liquidity or sparse closing data can make the comparison noisier.

How do I track CLV if I’m betting live?

Define a consistent later reference and record its timestamp. That comparison is a live price-movement measure, not necessarily the same benchmark as a pre-game close.

── Track Your CLV with Evrai ──

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Compare matched sportsbook entry and closing prices. Review Kalshi and Polymarket positions with separate fair-value measures where independent at-fill estimates exist.

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