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What Causes Line Movement? (Sports Betting)

by March 5, 2020

In sports betting, it’s essential to find an edge if you want to turn a long-term profit. That’s why it’s essential to monitor the line moves at sportsbooks before placing a bet. Along with getting the best possible price for your wagers, tracking and understanding line movement can separate winning and losing sports bettors.

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What Causes Lines to Move?
Simply put, line movement occurs when more money is placed on one side of a game compared to the other. This mainly happens to the point spread or the over/under total. The main goal for oddsmakers is to garner as much action on both sides. That way, the sportsbook will make money regardless of the outcome, based on the commission they charge.

Getting exposed is the worst-case scenario for sportsbooks. If there is a significant amount of interest on one side of a bet, the book will attempt to drum up interest by making the less popular side more attractive. Line movement can also happen due to external factors such as suspensions or injuries.

Public vs. Sharp Money
Another key to understanding line movement is to interpret the difference between the number of bets on one side compared to the amount of cash on one side. Not all bets have the same impact, and sportsbooks know who their consistently profitable customers are. Professional bettors, known as “sharps,” are responsible for the biggest swings in line movement.

An influx of sharp money causes books to react and adjust immediately. “Public” money represents the average bettor who tends to lose more than they win, so shops won’t put much stock into who the public backs.

What is Reverse Line Movement?
Sportsbooks shift their lines based on the money amount, not the bet percentage amount. Let’s say the Los Angeles Lakers and Memphis Grizzlies are set to square off in the NBA, and the Lakers are tabbed as 7.5-point favorites.

If there are 100 bets placed, and 70 of them are on the Lakers, you might think the line is going to move in the Lakers’ direction. But if the total amount of money on the Lakers is only $5,000, and the 30 Grizzlies bets add up to $10,000, the line will move toward Memphis. This is called reverse line movement.

The variable of sharp money coming in on Memphis means the sportsbook will do anything it can to get more action on the Lakers. To not get exposed, the Lakers line would likely move to -7 or -6.5, depending on how much the sharps are betting.

Don’t Be Afraid to Wait
Not all above average sports bettors get their wagers in as early as possible. Instead, many bettors wait until an hour or two before the game to see how the market has reacted throughout the day. If you locked in the Lakers at -7.5 when the odds opened, but you have since come to find out LeBron James is sitting, you’re going to be holding an L.A. ticket with a bad line.

Getting the best possible line is crucial to making money in sports betting. Don’t be afraid to shop around at different books to find the best price. Being diligent and aware of how books operate is imperative to maintaining a profit in the long run.

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Luke Miller is a featured writer at BettingPros. For more from Luke, check out his archive.

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