How to calculate Closing Line Value (CLV) in sports betting
Updated: Apr 14, 2022
What is Closing Line Value and why it's important for sports bettors
How to calculate CLV
How to improve your CLV
Closing Line Value, or CLV, is one of those controversial topics among sports bettors. You'll have sharp bettors like Spanky preach the living crap out of CLV on Twitter and on his podcast Be Better Bettors. Still, you have plenty of well-known bettors (some good, some not so much) who deny it's a useful number at all.
From a statistics point of view, I agree with Spanky that CLV is crucial for bettors looking to step their game up. In this article, you'll have a better understanding of what it is, how to calculate CLV, and how to improve it.
By the end of this, hopefully you'll agree CLV is useful for you as a bettor and you'll know how to calculate it!
What is CLV?
Before we discuss what closing line value is, let's start with what the closing line is. Between the time the sportsbooks like DraftKings or BetMGM release the odds, and the time the game begins, the odds can change. This occurs when new information is discovered such as player injuries or weather. It can also change when the public or sharp bettors favor one side of the line or the other.
The Cincinnati Bengals opening line could be +4.5 on Monday, but a key player injury, inclement weather, sharp money, or any other factor could change that line to a +2 closing line by the time the game starts the next Sunday.
In short, the closing line value is the difference between the line you placed your bet at, and the closing line, measured in a percentage.
Let's take the above example. If you had favored Cincinnati to beat the spread and you bet at the opening line of +4.5, and the closing line was +2, you would have positive CLV. Nice job!
Why? Because betting that the underdog (Cincinnati in this case) will lose by less than 4.5 points is a much easier feat than them having to only lose by less than 2 points.
The rule of thumb is - If the closing line is less than the line you bet at, you have positive CLV. If the opening line is -3 and the closing line is -3.5, positive CLV. If the opening odds (for a moneyline bet) is +120 and the closing line is -105, positive CLV. If the opening line is +6 and the closing line is +7.5, negative CLV.
Get the idea?
The rule of thumb - If the closing line is less than the line you bet at, you have positive CLV.
Why CLV is important for improving as a bettor?
Winning bets and cashing tickets is a tell-tale sign you're doing something right. But believe it or not, it's far from the whole picture. And chances are if you aren't paying attention to your CLV, statistics say your luck will soon run out.
CLV enables bettors to have a more clear picture of how they will do in the long run, which is more important than the winning periods and losing periods we all experience as bettors.
Let's go back to that Cincinnati Bengals example. Let's say Cincinnati has a statistically worse-than-average game and ends up losing 35-28, meaning your +4.5 spread bet lost. Initially, most would consider this a bad bet because you lost money. However, if you followed your CLV, you would notice that it was positive because the closing line was +2!
What this means is although you lost this game, statistically speaking, it was a good bet, and over the long run of making similar bets, you would come out on top!
CLV enables bettors to have a more clear picture of how they will do in the long run, which is more important than the winning periods and losing periods we all experience as bettors.
How to calculate CLV for MLB/UFC/NHL bets, and ALL moneyline bets
Step 1 - Find the Win Probability for the line you bet at
Do this by taking the odds you bet at. If the odds are negative (i.e. -110) use this formula:
(a) Win Probability = Odds / (Odds - 100)
If the odds are positive (i.e. +130) use this formula:
(b) Win Probability = 100 / (Odds + 100)
Step 2 - Find the Win Probability for the closing line
Obtain the closing line from the Vault bet tracking app on the odds table, or anywhere you get odds from. Then, simply use the same formulas from above for the Closing Odds. If the closing odds are negative use this formula:
(c) Closing Win Probability = Closing Odds / (Closing Odds - 100)
If the closing odds are positive use this formula:
(d) Closing Win Probability = 100 / (Closing Odds + 100)
Step 3 - Calculate the CLV
Use the following formula for calculating CLV:
(e) CLV = 100 x ((Closing Win Probability - Win Probability) / Win Probability)
Example: You place a bet on the Milwaukee Brewers (MLB) spread -3 (-110), and the line closes at -2 (+105). First, calculate the win probability of your bet using formula (a) [ -110 / (-110 - 100) = 0.5238 ]. Then, calculate the closing win probability of your bet using (d) [ 100 / (105 + 100) = 0.4878 ]. Finally, calculate your CLV using formula (e) [ 100 x (0.4878 - 0.5238) / 0.5238 = -6.87 ]. So you had a poor CLV of -6.87% in this instance.
How to calculate CLV for NFL/NCAAF/NBA/NCAAB spread and total bets
Step 1 - Get the Win Probability for the line you bet at
Do this by taking the odds you bet at. If the odds are negative (i.e. -110) use this formula:
(f) Win Probability = Odds / (Odds - 100)
If the odds are positive (i.e. +130) use this formula: