CLV (Closing Line Value)

Closing Line Value (CLV) is the difference between the price you bet at and the closing line—the final odds when a game starts. It's the gold standard metric for measuring betting skill in sports betting.

Why CLV Matters

Here's the counterintuitive insight: even if you lose a bet, positive CLV means you made a good bet.

The closing line represents the market's best estimate of true probability. It incorporates all available information, including sharp money, injury news, and late market moves. If you consistently bet lines before they move in your favor, you're demonstrating genuine edge.

Example

Say you bet the Bills at -3 on Tuesday. By kickoff Sunday, the line has moved to Bills -5.

You captured 2 points of CLV. Even if the Bills win by exactly 4 (covering your bet but not the closing line), you made the sharp play.

Conversely, if you bet Bills -7 and the line closes at -5, you have -2 CLV. Even if the Bills win by 10 and you cash, you paid too much for the position.

CLV as a Predictor

Academic research and professional experience confirm: long-term CLV correlates strongly with profitability.

A bettor with positive average CLV will be profitable over sufficient sample size. The closing line is efficient enough that beating it consistently is the functional definition of sharp betting.

This is why sportsbooks track CLV to identify sharps. Win or lose, if you're beating the close, you're getting limited.

Measuring Your CLV

To track CLV:

1. Record the line when you place each bet
2. Record the closing line at game time
3. Calculate the difference (your line minus close, adjusted for side)
4. Track average CLV over time

Positive average CLV = you're finding edge. Negative average CLV = you're paying too much for your positions.

CLV in Prediction Markets

On platforms like Kalshi, CLV translates to the difference between your entry price and the final market price before resolution.

If you buy YES at 40¢ and the market closes at 50¢, you have +10% CLV. The market moved to agree with your position—a bullish signal for your thesis regardless of outcome.

The Closing Line Isn't Perfect

Important caveat: the closing line is efficient but not omniscient. It reflects market consensus, which can be wrong. However, it's efficient enough that consistently beating it indicates genuine skill or information advantage.

Related Terms

• Sharp — Bettors who consistently achieve positive CLV
• Steam — Rapid line movement that creates CLV opportunities
• Stale Line — Prices that haven't updated with new information