Sportsbooks are constantly adjusting lines to keep the betting markets balanced. In a perfect world, they want the exact same amount of money bet on both sides of each game because this not only guarantees them a win, but also means they have zero risk. When one side is getting significantly more action than another, the sportsbooks risk of losses increases. To combat that, they move the line which will entice more people to bet on the other side.
That’s the basics of line movement as it applies to sports betting. Reverse line movement is a more advanced concept that occurs when the line movement of a game contradicts the public betting percentages. Although this might sound complicated, it really isn’t. In fact, once you know what to look for you will be able to spot reverse line movement trends quickly and easily!
Sports Betting Line Movements In General
Before we jump deeper into reverse line movement, I first want to talk a little bit more about line movements in general. If you’re already familiar with how a line should move based on action then you can skip ahead to the next section. Otherwise, let’s discuss why sportsbooks want to have as close to even money being wagered on both sides of any action as possible.
Although some people believe the fairy tale that sportsbooks can somehow control the outcome of a game, this simply isn’t true. All a sportsbook really wants to do is set an opening line that they feel will attract bettors to both sides. If they are getting uneven action on a game, they will move that line to try and get more bets on the other side. This theory applies to the money line, spread and total. For example, let’s say a team opens as a 6-point favorite. If 70% of the bets coming in are on that team to cover, the books are vulnerable. If that team were to end up covering then the juice they make off the losing teams bets wouldn’t cover their overall losses. That’s why they would often be quick to move the line. In this case, you would probably see the line go up to something like -6.5 or -7.
Why is this done? Because the sportsbooks have a built-in profit margin called vigorish, also referred to as vig or juice. For example, if both sides of a spread or total is -110 (you bet $110 to win $100), then the extra 10 cents you’re being charged on each dollar you bet is the juice which the loser will pay to the sportsbook. Books don’t need to “control” any game because if the action is split evenly then they’re guaranteed to make money no matter what the outcome might be. If 50% of money is bet on the favorite and 50% of money is bet on the underdog in the example above, then money is simply taken from one side and paid out to the other (no matter who wins the game) and the sportsbook gets to keep the vig from the losing side. This is the ideal spot for a sportsbook to be in because it limits their risk and guarantees them a win. It’s also why they are constantly moving the lines around before a game. If action on a game is unbalanced, then sportsbooks risk taking a loss.
One important thing to know is that the number of people betting on a particular game is not what moves the line. Big bets are what moves a line and this is partly why using reverse line movement as a strategy can actually be profitable. Although the number of bets and money coming in is important, sportsbooks often know who the professional gamblers are and will pay attention to those making large wagers. If a sharp bettor comes in and lays down a max bet, you can be guaranteed that line will move. The best sportsbooks aren’t afraid of sharp action. Instead, they use those bets as information and sharpen up their lines because of them. Weaker books limit or ban winning players because they only want recreational bettors who will lose on a regular basis.
Where To Find Reverse Line Moves
You might be wondering, how does someone know which side is receiving a majority of the money or tickets? There are actually several sites out there that will show you the percentage of bets being wagered on each side. Zcode System has a line reversal tool which automatically detects sharp line movements and points them out to you, making them significantly easier for you to find. However, I personally use the Game Center at Pregame to look for reverse line movement and this is what I will be using to show you a clear example of reverse line movement below.
Remember, lines are constantly moving before a game and it isn’t unusual for big bets to come in at the last minute. With that in mind, you should hold off until right before the game starts to place bets using this strategy. The line might move one way several hours before the game, but then shift back right before it begins. Wait until right before the line closes to confirm the trend is legitimate!
How To Spot Reverse Line Movement
It’s really easy once you’ve figured it out. Let’s breakdown the screenshot below which is the closing lines and details for NBA basketball games that took place on December 8, 2022.
Notice that we can see the opening line, closing line, percentage of cash, percentage of tickets, and final result recorded for each of the three games. Can you spot which one has a reverse line movement trend? Let’s quickly discuss each of the three games.
In the first game, Clippers vs. Heat, we see that cash and tickets were fairly even against the spread. They were slightly heavier on Miami, but yet the line closed an entire point and a half higher than it opened. This would be a clear sign that Miami definitely had some big bets come in on them, likely from sharp professionals or whales. As for the total, although tickets were slightly heavier towards the over, cash was actually heavier towards the under. This usually means the general public was liking the over while sharper bettors (those placing larger bets) were liking the under. We get some confirmation on that by seeing how much the total moved down from where it opened. The total opened at 215.5, but moved all the way down to 211 with 63% of cash bet on the under by game time. It’s not like 90% of cash was bet on the under in this game, so if I saw this it would be a clear sign that there were some very large bets placed on the under. That’s why the total moved down 4.5 points even though only 63% of cash was actually bet on the under. Remember, it’s usually large bets that move lines, not the number of tickets or number of small bets that come in on a particular side. Overall, this game has no reverse line movement, but it looks great for the books. The earliest sharps who got Miami at -5 and the under at 215.5 won, but everyone else who tried to follow but missed the best lines either pushed or lost. As previously mentioned in this article, the books want things to be as close to 50% as possible to limit their risk, and we can see that’s pretty much what they got here!
The second game, Rockets vs. Spurs, is where we want our focus to be. We can see that both tickets and cash were heavier on the over in this game, yet the total has actually moved down 4 points. This is a clear sign of reverse line movement on the total because the line has moved the opposite direction of where cash and tickets are the heaviest. This would mean that of the 37% of cash currently bet on the under, there were some really big bets in there. The line likely moved several times to swing four points which means there were likely several large bets that came in. As for the spread, we can see that both tickets and cash were heavier on the Spurs, yet the line actually went from Rockets +2 to Rockets -1.5 before the game started. Once again, this is a clear sign of reverse line movement on the spread because the line has moved the opposite direction of where cash and tickets are the heaviest. Just like before, of the 43% of cash bet on the Rockets in this game, there had to have been some pretty large bets in there to move this spread 3.5 points. Overall, this game did have reverse line movement on both the total and the spread. If you followed this trend on the total then it was an easy winner, but if you followed against the spread then it lost. One thing that’s still important to note here is that the books still kept those numbers around the 50% range. Although percentages were in the sixties for the total, the game actually went under making them extra money.
We won’t spend any time covering the third and final game on this card because we can see that there was no significant line movement when it started. Cash and tickets were heavier on the over and the game did end up going over, which means the books lost some money here. If sportsbooks always won and were able to “control” games, this particular game (which Pregame recorded over $200K in bets on the total, of which only 23% were on the under) would have gone under instead of costing them over $100K. However, they did manage to keep the spread percentages practically even again.
Is Reverse Line Movement Good Or Bad?
Now that you know more about reverse line movement and how to spot it, you might be wondering if it’s a strategy that is profitable to follow. The answer to that is yes, but you have to trust it long term. The important thing to remember is that reverse line movements are almost always the result of sharp bettors. Almost every time you make a bet because of a reverse line movement trend, you are betting along side the sharps. However, that doesn’t mean you will always win. As we saw from the example above, the reverse line movement trend was both a winner and a loser in the same game.
My recommendation is to add reverse line movement trends as another tool that’s available to you when handicapping games. Don’t go solely off of it and instead use it as something that, when put together with other factors, can make your bet stronger. For example, you know that one team is playing the tail end of a back-to-back while the other team is playing with the rest advantage. You like the team playing with the rest advantage and right before the game you notice reverse line movement favoring your team. Look at that as confirmation in your pick and lay the hammer down!
Reverse line movement works the same way whether you’re looking at the money line, spread or total. As long as you can see the percentage of money and tickets bet on a specific game, you’ll be able to tell if the line is moving with those numbers or against them. If it’s moving against them then it’s a clear sign of reverse line movement. Just remember, lines can always change in the final minutes before a game starts and a reverse line movement trend can’t be confirmed until the line closes. If you consider other factors when handicapping games, such as previous matchups between teams or player stats, then using reverse line movement as a confirmation signal for your picks is a great idea!