Why Lines Move


A lot can (and often) happens between the time the line opens and closes. But what are the factors that make it move and when is the best time to get in? Let’s take a closer look at how this pricing works and how you can take advantage of it.


The opening line is set by the odds makers based on a number of factors. They’re the experts: they keep a close eye on what’s happening in the sports (momentum, injuries, history) and set a price. From there, the market opens up to supply and demand.


    For the most part, sportsbooks will tell you that their goal is to get even action on both sides of a game, so that they can merely collect their commission (or “the juice”). That means that supply and demand comes into the play here, which means that will affect the line movements. Let’s use this as an example:


          1. Green Bay Packers -10.5
          2. Cleveland Browns +10.5

    Let’s say 10 people come in and place bets on the Packers. Now all of the sudden the books have to move the line to make the Browns more attractive to generate some action on that side. So they might move the line to +11 or +12. Then once that catches the eyes of bettors, it should settle the line back down.

    This supply and demand is one key factor as to why the lines are jumping around a lot.


    The other key element to this equation is what the sharps are doing. Sharps are known as professional bettors and ones who have a keen understanding of what’s happening – better than the average Joe. When they place their bets, the odds makers pay attention because those are the players that win for a living. Their opinions are respected a lot more. Although the goal of the sportsbook is still to get 50/50 action on both sides, sharp money is weighed more heavily into the equation than the public.


    When people talk about taking advantage of line moves, it usually means tailing the sharp moves. Again, sharps are the players who win more than anyone else, so if a line move is deemed as “sharp”, you could also bet that line afterwards and be on the same side as the sharp. If you’re just a casual bettor, this is one way of leaning on the expertise of someone who has done their research.

    However, this is a flawed logic more often than not. For starters, sharps will always get a better price. For example, let’s say a group of sharps like the New York Yankees at -140. If some big money comes in on the Yankees, then the odds makers will adjust the line as a result. That means when you come to click away, you’re bet on the Yankees might have to be at -150 or -160. While it might not seem like a big deal, that price difference is very significant over a long period of time.

    Also, keep in mind that sharps come back on sides. In other words, they might place a $1000 on the Yankees early in the day and hope that other bettors follow them to push the line a certain way, and then later come back in the day and bet $5000 on the Yankees’ opponent.

    Unless you work for the sportsbook, it’s hard to determine what a sharp move is to begin with and beyond that, following those plays isn’t a foolproof system.


    The best way to take advantage is to notice the sharp moves and incorporate it into your handicapping. If you liked a side before and now you seem some sharp money come in on it, that further reinforces that you’re making a good play. If you see sharp money come in against you, you may decide to make a smaller play or leave things unchanged. After all, even the best sharps are only right about 60% of the time.


    Remember that not all line moves are related to action. In baseball, you might see a line change if a starting pitcher gets scratched and someone else has to step in on short notice. In football, you might see a huge line move if snow and wind enter the forecast of a game that was previously supposed to be clear. In the NBA, you might see a big jump in a line if a head coach decides to rest his stars last minute (see: Gregg Popopvich). All of these are other examples of why a line might move. It’s your job to keep track of the news and determine why the lines are moving around.