Winning sports bettors go into every wager they make with a mission, and it isn’t just to make a profit.
While that’s a goal as well, of at least equal import is to beat the closing line. Beating the closing line on a consistent basis across a large volume of bets should bring long-term winning results. It reflects an edge in the market, and it’s a feat worthy of great respect in this game.
If you pay attention to winning sports bettors’ discussions of their action, you’ll often see them talking about it. If you see their betting logs, they’ll often have a column or a place to track it. They care about it, and so should you.
So, what does it mean to beat the closing line when betting on sports? Why is it important and how can you start tracking it?
What is Closing Line Value?
Closing line value is the price a bettor gets relative to the closing price. If they beat the market, they got positive CLV. If the market beat them, they got negative CLV.
Beating the market means getting a better price than the closing price. For example, imagine you bet an NFL team as a -3 favorite and then check the line before kickoff. It’s at -3.5. You got closing line value.
If you see them close -2.5, you got beat by the closing line and probably made a bet with negative expected value (-EV).
All of this assumes the price was -110 on these bets, or -105 if you have access to a generous bookmaker. You aren’t accomplishing quite as much if you bet a team +7 (-110) and the line moves to +6.5 (+100), though this would still be a bit of CLV.
Why does closing line value matter?
A betting line is a reflection of implied probabilities. If a vigorish-free (no take from the bookmaker) market offered exactly +100 on both sides of a two-way market, it implies a 50% chance of either outcome.
When a line opens, it represents the originator’s best estimation about the probabilities of the event. Over time, more information – and more wagers – pours into the market, moving the line closer to its closing price. Limits get larger as the books become more comfortable with the accuracy of the market. The line becomes sharper and sharper as it gets closer to closing.
“Betting markets are the sum of all prediction models.” A favorite sports betting Twitter follow used to say this, and it’s a good way to think about the markets.
Whether they’re Joe Superfan betting his favorite team or syndicates using sophisticated algorithms, by the time the market closes, all the models have given their input.
Of course, some models weigh more heavily than others. It’s up to the bookmaker to decide how much weight to give each wager and adjust the line accordingly.
Therefore, the closing price gives the most accurate estimation of the probabilities in the market. Specifically, the closing price of books that take high-limit wagers represent the most accurate look at these probabilities.
So, if you bet a team +100 and they close +120, the market is telling you the true probability is closer to 45%. You bet that they had at least 50% win probability, so you’ve taken the worst of it according to the market.
Of course, 45% is still pretty high. But if it comes home, you should usually be counting your blessings and trying to figure out how to make a better bet next time rather than feeling like you were right and the market was wrong.
In spread betting, it’s even easier to see why closing line value matters. If you bet a team -7.5 and they close -6.5, the game will land on 7 some percentage of the time. In these instances, getting a good number would have been the difference between a win and a loss.
While a move off a key number creates an obvious example, even little-valued numbers can make a difference. A game from the 2019-20 NFL Divisional Playoffs illustrates such an instance.
In the final game of the weekend, the Green Bay Packers hosted the Seattle Seahawks. The line opened around Packers -4 at most books and moved to -5 as it jumped around during the week before closing back at -4.5.
Final score: Packers 28, Seahawks 23, landing on -5 that most bettors probably didn’t mind taking if they liked Green Bay.
How to track closing line value
You’ll often see players in moneyline sports track their closing line value in terms of “dollars and cents.” For example, a bet on a team at -120 that closes at -130 generated “10 cents” of CLV. This is a simplistic way to track it that will suffice for bettors who want a fast and easy way of calculating their CLV.
However, this ignores some relevant info. First, it doesn’t take into account the vig. Plus, not all “cents” are created equally. A move from +100 to -150 is a larger one in terms of win probability shift than -250 to -300.
Aspiring serious bettors can get a much more accurate gauge of their CLV with a little extra work.
It starts with calculating the no-vig, or juice-free, line at close. This can be done using free calculators available online by simply plugging in the two sides of the market. The calculator will spit out the no-vig line and implied probability, eliminating the bookmaker’s take from the equation.
Then, take the price you bet and compare it to the no-vig closing price. The formula: [(X-Y)/Y]x100. X is the implied probability at close and Y is the implied probability of the bettor’s wager.
For spread betting, the bettor needs to see the price being charged for the line they got. This can be done with free-to-use half-point calculators available online. Simply plug in the current line and scroll back to see what the price would be for the bettor’s line. The difference in these prices can be used in the above formula to calculate CLV.
How to beat the closing line
Now that you know what closing line value is and why it matters, the obvious question is: how do you beat the closing line?
The simple answer: make winning bets. The line will move in your favor and you will beat close.
Of course, that’s far easier said than done. People who can consistently make winning bets and beat the market are often playing professionally and they aren’t exactly looking to give away their strategies.
Even recreational bettors can give themselves a better chance to beat the market with a few simple strategies.
First, and most obviously, have access to multiple sportsbooks so you can line shop. All of the sportsbooks tend to have “group think” of sorts as they follow the moves at the influential books. However, sometimes they can be slow to move a line, or they need to inch a half point off for risk management reasons. In these cases, you can get easy value because the line should eventually converge where the high-limit books are sitting.
Another key general rule is that it’s better to get in the market earlier than later. This is where the recreational bettors have an advantage over the high-limit players. They have to wait until the limits increase to get their big bets down, which then start moving the market.
That’s not a concern for most recreational bettors. If they can correctly anticipate where the influential players are on a side, they can get their bets in before the lines move and avoid “chasing steam” – following the sharp plays after the value has been bet out of a line.
Of course, if you like a side that you think is the opposite side of the influential bettors, betting later usually gives you the chance to get the best number.
You may not beat close but you will at least get the best number possible. An age-old axiom about sharp players is they don’t bet teams, they bet numbers.
Finally, think deeply about what changes in the betting ecosystem mean. Injuries are an obvious example but an even bigger one can be changes in the rules. The betting market can misadjust to such things and create opportunities for value.
You can be sure the sharp players will make the necessary adjustments at some point, but if you are on top of things early, you give yourself the best chance to beat the closing line.