When you first start out in sports betting you might get the idea that the spread for a football game is fixed – it’s set at the beginning of the week and that’s where it stays. That’s certainly how the mainstream media talks about it on the rare occasions they acknowledge the point spread. The truth, of course, is that point spreads are far from fixed – tat they react to the bets that are made and adjust accordingly. Sometimes those adjustments are small, while other times we can see the lines move by several points – sometimes in a short amount of time. It’s those big moves that I want to focus on today. Let’s look at some things that cause big line moves, why they are interesting to sports bettors, and one key thing to keep in mind when thinking about them and making your bets:
Causes
Early money jumping on a mistake – There are a lot of people – smart guys with a lot of money to bet – who have already established what they think the lines should be before the books release them. As soon as they are out those bettors will aggressively make bets if the line differs significantly from what they think they should be. If a line is posted that a lot of bettors disagree with then the early action will be fierce, and the line will quickly move to correct that mistake and slow down that heavy action. Line moves like this can be as big as two or three points, and they will take place before most people wake up on Monday morning in most cases.
Consistent money on one side – Sportsbooks are, at least theoretically, trying to get balanced betting action on both teams. If the same amount of money has bee bet on both sides then the books are guaranteed to make a profit no matter what happens in the game because half of the bets will win, the other half will lose, and the books get to keep the juice on the losing bets. In some cases books are comfortable with unbalanced action – if they are willing to take a gamble at the chance of increased profit for them. For the most part, though, they want it as close as they can get it. When a large percentage of the money comes on one side, then, the books will move the line to make the other side more attractive. The more lop-sided the action, the bigger the potential line move.
Injury or personnel change – Sometimes a key injury will cause a line to move significantly. Say, for example, that Peyton Manning was hurt in practice on Tuesday and was out for Sunday’s game. The line was set with him in mind, so it would have to adjust significantly if Curtis Painter was going to be the starter instead. Major injuries, suspensions, trades (though those are obviously very rare in the NFL during the season), and other major personnel changes could be responsible for big line moves.
Factors like weather – Sometimes a weather forecast can change dramatically after the lines have been set, and that weather can cause the line to adjust. For example, if a team that relies heavily on the pass is suddenly playing in a game that will be played in the driving wind, bitter cold, and driving snow then they likely aren’t as attractive as they would have been if it was clear and calm. In particularly severe cases like this the books might move the lines significantly themselves before the betting action forces them to do so.
Big line moves are interesting when:
The move goes in opposite way of bulk of action – If you keep an eye on the public action – the teams that have drawn the majority of the bets placed on a game – then occasionally you will see a line move that doesn’t make sense. In these games the large majority of public action will be on one team, yet the line will fall to make that team less attractive. That obviously wouldn’t happen most times if the majority of money were on the more popular team. What it tells us, then, is that though most of the bets have been on one team, a few of the bets on the less popular team have been particularly big – bigger than all the bets on the popular team combined. When bets that big are made it’s a pretty good indicator that someone who invests a lot of time and money in betting has a strong opinion. That’s something worth investigating for yourself.
The move goes through a key number – Books hate moving a line through a key number – especially three. The reason for that is that they are vulnerable to being middled when that happens, and books can lose a lot of money when they are middled a lot in one game. When a book does move a line through a key number, then, you can be sure that there is a very strong reason for it – that not moving it would put them at bigger risk of a loss than the middle would. A line that moves through a key number, then, is definitely worth a close look because you know something interesting is at work.
The move is particularly big – We’re used to seeing line moves of up to a couple of points all the time. It’s not at all surprising when a line moves that much. Sometimes, though, a line will move by five or six points. When that happens then something really bizarre has gone on, and you definitely need to try to figure out what it is.
The key to betting big line moves is:
Anticipating them before they happen – In some cases line moves come as a surprise that we couldn’t have predicted before they happen. Most times, though, you can see a big line move coming. For example, you won’t be surprised if a line move happens when a public team is playing a very unpopular one. When you can anticipate big moves like that then it is in your best interest to use that movement to your advantage. If you like the public team in a case like that then you’ll want to make your bet as early as possible before the line gets less attractive. On the other hand, if you like the chances of the less popular team you’ll want to be as patient as you can because the spread is likely to get more and more attractive for you as game time nears.
