How Often Should the Line Move?
Understanding Sportsbook Industry Standards: Download the Full Report
Line movement is a helpful indicator for sports bettors. Keeping an eye on shifting odds in the lead-up to a sporting event is one the most reliable ways to determine which side of the wager is favored by the betting public and the high rollers, or sharps.
Sportsbooks will move the line, (i.e. change the odds), for two distinct reasons: because of game-related factors such as an unexpected injury or drastic change to the weather, or to attract more action on one side of the betting line.
Some sportsbooks are more reactive to these factors, adjusting the line frequently in the days and hours leading up to a sporting event. Other books take more of a ‘set and forget’ approach, only changing the odds when absolutely necessary.
It’s important that you choose a sportsbook that adjusts the betting lines with a frequency you’re comfortable with. Bettors who pursue a handicapping strategy that relies on evaluating odds movement will want to bet with a more responsive sportsbook. Those who want to place their wagers at any time during the week knowing that the odds are locked in will prefer betting with sportsbooks that adjust their lines less frequently.
Sports Betting Dime collaborated with graduate students at a leading research university to determine the industry standard for line release times and help consumers understand what to expect when logging in to their online sportsbook.
Establishing Industry Standards
Our research team pulled data from 12 online sportsbooks, evaluating how many times the odds changed in the lead up to each game during the 2018 NFL season.
For the purposes of this study, we evaluated only how often the line moved in the week leading up to each game. Live, in-game odds tend to fluctuate continuously throughout the game and were left out of this analysis as a result.
Line movement was evaluated for the three most popular types of NFL wager: moneyline, point spread, and totals (over/under). The numbers displayed in the table below are the average number of times the odds changed, per game, for each bet type evaluated.
Industry Standards for Line Movement
| Wager Type | Industry Standard |
|---|---|
| Moneyline | 1.96 moves per game |
| Point Spread | 0.21 moves per game |
| Totals | 0.14 moves per game |
As you can see, the data clearly supports the fact that line movement (when defined as changes to the odds specifically) is primarily a phenomenon that affects moneyline wagers. The sections below include a detailed discussion of how line movement operates differently for point spread and totals wagers.
Line Movement: All Wager Types
| Rank | Average # of Line Moves Per Game |
|---|---|
| 1 | 0.26 |
| 2 | 0.27 |
| 3 | 0.29 |
| 4 | 0.53 |
| 5 | 0.55 |
| 6 (Tie) | 0.73 |
| 6 (Tie) | 0.73 |
| 7 (Tie) | 0.91 |
| 7 (Tie) | 0.91 |
| 8 | 1.23 |
| 9 | 1.28 |
| 10 | 1.53 |
These numbers can be taken as a high-level indication of how often you can expect betting lines to move, but the differences between various wager types are significant.
Let’s take a more detailed look at how line movement differs by bet type.
Moneyline Line Movement
| Rank | Average # of Line Moves Per Game |
|---|---|
| 1 | 0.6 |
| 2 (Tie) | 0.7 |
| 2 (Tie) | 0.7 |
| 3 (Tie) | 1.3 |
| 3 (Tie) | 1.3 |
| 4 (Tie) | 2.1 |
| 4 (Tie) | 2.1 |
| 5 (Tie) | 2.3 |
| 5 (Tie) | 2.3 |
| 6 | 3.1 |
| 7 | 3.2 |
| 8 | 3.8 |
The data suggest that bettors can expect to see the moneyline odds shift approximately two times in the week leading up to an NFL contest. In addition to exhibiting the most odds movement of all bet types evaluated, the moneyline also showed the greatest variance between sportsbooks in terms of how often the odds changed.
- Five of the 12 sportsbooks were most likely to see the line move once in the lead up to the game
- Four of the 12 were most likely to see the line move twice in the lead up to the game
- Three of the 12 were most likely to see the line move at least three times in the lead up to the game
Point Spread Line Movement
| Rank | Average Number of Times Line Moves Per Game |
|---|---|
| 1 | 0.06 |
| 2 (Tie) | 0.07 |
| 2 (Tie) | 0.07 |
| 2 (Tie) | 0.07 |
| 3 | 0.18 |
| 4 (Tie) | 0.22 |
| 4 (Tie) | 0.22 |
| 5 | 0.26 |
| 6 (Tie) | 0.27 |
| 6 (Tie) | 0.27 |
| 7 | 0.41 |
| 8 | 0.44 |
Generally speaking, the 12 sportsbooks evaluated in this study did not adjust point spread odds during the 2018 NFL season.
The sportsbook with the most odds movement on point spread lines averaged only 0.44 moves per game. This sportsbook also saw the most movement on both the moneyline and totals lines. The sportsbook with the least amount of point spread odds movement averaged just 0.06 moves per game.
On average, the point spread odds changed an average of 0.21 times from line release to kick off for each game during the 2018 NFL season. These data suggest that bettors should not expect to see odds movement on the point spread as an industry standard.
Totals Line Movement
| Rank | Average Number of Times Line Moves Per Game |
|---|---|
| 1 | 0.01 |
| 2 (Tie) | 0.03 |
| 2 (Tie) | 0.03 |
| 3 | 0.04 |
| 4 | 0.06 |
| 5 | 0.11 |
| 6 | 0.14 |
| 7 (Tie) | 0.17 |
| 7 (Tie) | 0.17 |
| 8 | 0.24 |
| 9 | 0.33 |
| 10 | 0.34 |
As with the point spread, odds were unlikely to change on totals lines at all 12 sportsbooks evaluated. Compared to the point spread, totals lines exhibit even less odds movement. A follow up study will be required to evaluate each sportsbooks’ proclivity for adjusting the spread and totals themselves.
- Sportsbooks almost never adjust the odds for totals lines
- Pre-game totals odds movement ranged from an average of 0.01 – 0.34 moves per game
- Bettors evaluating movement in totals lines should focus their efforts on the total itself, not the odds
The sportsbook with the most odds movement on totals lines adjusted the pre-game odds an average of 0.34 times per game. The sportsbook with the least amount of odds movement on totals lines exhibited a statistically insignificant 0.01 odds adjustments per game.
On average, totals odds changed just 0.14 times per game during the 2018 NFL season. These data suggest that bettors should not expect to see noticeable odds movement on NFL totals lines when laying wagers before the game begins.
Why Don’t the Odds Change on Point Spread and Totals Lines?
Any of you who’ve made it to this point in the analysis are surely wondering why line movement is the norm for moneyline wagers but is virtually non-existent when it comes to point spread and totals lines. The answer relates to the nature of these wagers themselves and the options available to sportsbooks when they need to adjust the terms of the wager.
Sportsbooks may need to adjust the terms of a wager in response to game-related developments such as an unexpected injury, lineup change, or drastic change to the weather. They’ll also do so to ensure each side of the bet is receiving relatively equal action. After all, this is how the sportsbooks guarantee themselves a profit.
Moneyline wagers ask bettors to choose the winner of a sporting event straight up. Because this is a simple A vs B proposition wherein outcome A and B themselves cannot be adjusted, changing the odds is the only way sportsbooks can adjust the terms of the wager.
With a point spread, the book can change option A or B by giving or taking additional points. This changes the terms of the wager without needing to adjust the odds associated with each outcome. Totals fall into the same category: changing the total fundamentally changes option A and B, because the over vs under is now in relation to a different number.
If the Odds Don’t Change, How Do the Spread and Total Account for Changing Conditions?
For example, let’s suppose a star player sustains a major injury two days before a high-profile NFL matchup in which his team was heavily favored. The chances of his team winning the game have now decreased substantially, and the sportsbook needs to adjust their betting lines accordingly.
On the moneyline, the book will have to place his team at longer odds. There’s just no other mechanism to reflect their decreased likelihood of winning the game, so they might move from something like -250 to -300.
On the point spread, however, the book can reflect their decreased advantage by closing the gap slightly on the spread. By moving the spread from +/-10 to +/-6.5, the book has changed the terms of the bet to more accurately affect the likely outcome. There’s no need for them to also adjust the odds.
Say the total for this game was set at 48, but this injury is likely to reduce the number of touchdowns the player’s team will score. Rather than maintaining the total at 48 and lengthening the odds on the ‘over,’ the book can simply lower the total to something like 44 or 41.5.
The bottom line is simple: bettors should look for odds movement on moneyline wagers, but they should monitor changes to the spread or total itself when evaluating shifts in implied probabilities on point spread or totals lines.
Looking for More Helpful Betting Insights?
This data highlighted in this article is pulled from a larger study aimed at determining industry standards among online sportsbooks. You can read the full report here.
As mentioned at the outset of this article, there’s no right answer to the question ‘how often should the line move?’ It really depends on personal preference and your handicapping strategy. Our list of sports betting sites is a great place to find the betting site that fits the way you like to wager.
Let's have fun and keep it civil.
