Closing line value: how to measure CLV on your bets

You bet a team at +150 on Tuesday. By game time, the same team is +130. Your bet lost. Was it a bad bet?

Probably not. You got a better price than the market settled on. That's closing line value, or CLV, and it's one of the most useful ways to grade your bets without waiting for hundreds of results.

What the closing line is

The closing line is the last price before a game starts. Lines open as an oddsmaker's estimate. Then news, injury reports and money come in, and the price moves. By close, the market has had the most information it will ever have before kickoff.

That's why the closing price is treated as the market's best estimate of the true chances. It isn't perfect. It's just harder to beat than any earlier number.

CLV asks one question: did you get a better price than that final estimate?

How to calculate CLV

You need three things: the price you bet, the closing price on both sides, and a calculator.

Step 1: Find your breakeven. Convert your price to implied probability. At +150, that's 100 / 250 = 40.0%. Your bet needs to win more than 40% of the time to profit.

Step 2: Remove the vig from the close. Say the game closed at +130 on your side and -150 on the other.

• +130 implies 43.48%
• -150 implies 60.00%
• Together that's 103.48%. The extra 3.48% is the book's cut.

Divide your side by the total: 43.48 / 103.48 = 42.02%. That's the no-vig closing probability.

Step 3: Compare. CLV = (closing probability / your breakeven) - 1.

42.02 / 40.00 - 1 = +5.0%

If the close was right, that bet was worth about +$5 for every $100 you put on it, even though it lost.

Don't skip the vig step

If you use the raw +130 price instead, you get 43.48 / 40.00 - 1 = +8.7%. That overstates your edge by more than half.

The vig step matters even more when the line doesn't move. Say you bet -110 and the game closes -110 on both sides. No-vig, each side is 50.00%. Your breakeven at -110 is 52.38%.

50.00 / 52.38 - 1 = -4.5%

Matching the close at standard juice is negative CLV. That gap is the price of playing. To get positive CLV, you need a number the market later moves away from, or a better price than everyone else is offering.

CLV on spreads and totals

On spreads and totals, the line can move in two ways: the number or the price.

When only the price moves, the math is the same as a moneyline. You take a team -3 at -110 (breakeven 52.38%). It closes -3 at -125, with the other side +105.

• -125 implies 55.56%
• +105 implies 48.78%
• Total: 104.34%
• No-vig on your side: 55.56 / 104.34 = 53.25%

53.25 / 52.38 - 1 = +1.7%

When the number moves, it's harder. Getting -3 when the game closes -3.5 is clearly good, but how good depends on how often games land exactly on that number. Some numbers matter much more than others. If you track these, use a half-point calculator rather than guessing, and read up on the hook.

Why CLV beats your win-loss record

Results are noisy. Here's how noisy.

Say your real win rate at -110 is exactly 52.4%, the breakeven. Over 200 bets, you'd expect about 105 wins. But random swings alone put you anywhere from about 91 to 119 wins, about 95% of the time. As a win rate, that's roughly 45.5% to 59.3%.

A bettor with no edge can look sharp or broke over 200 bets. The record alone can't tell you which.

CLV is different. You get a reading on every bet, win or lose. If most of your bets close at a worse price than you got, the market keeps moving your way after you bet. That's a sign your process finds value before the market does.

Where CLV is less reliable

CLV leans on the closing line being sharp. That holds best in markets where books accept large bets. More money and more information go into those prices, so their closes give the most accurate read on true chances.

Low-limit markets are different. Player props are the common example: books cap how much you can bet on them, so less money shapes the price. A closing prop line carries less information than a closing side or total. Positive CLV there is still a good sign. It's just a weaker one.

Also, one book's close can be off. If you can, compare against more than one book's closing price.

How to track it

You don't need software. A spreadsheet works. For every bet, log:

• Date, sport and market
• The price you got and the book
• The closing price on both sides
• Your breakeven, the no-vig close and the CLV percentage
• The result

After 50 to 100 bets, look at your average CLV. If it's positive, your timing and pricing are working, even through a cold streak. If it's negative, a hot streak is probably running ahead of your process.

Two habits push CLV up fast. Bet earlier, before news and money move the number. And shop prices across books. Every time you take -105 instead of -110, you start that bet ahead. Line shopping is the easiest CLV there is.

The short version

• CLV compares your price to the no-vig closing price.
• Formula: (closing probability / your breakeven) - 1.
• Always remove the vig from the close first.
• Judge yourself on CLV across many bets, not on one weekend's results.

The DARIMARKET board ranks every play by confidence and shows the price it needs to beat.