Opening lines are set by professional oddsmakers (also called traders or linemakers) who use proprietary models to calculate the probability of every possible outcome and price odds accordingly.
The Oddsmaking Process
Oddsmakers start with power ratings — numerical assessments of team quality built from statistics, recent performance, and expert knowledge. They apply adjustments for:
- Home field advantage (typically 2.5-3 points in NFL, similar in NBA)
- Rest advantages or disadvantages
- Known injuries to key players
- Weather forecasts for outdoor games
The raw power rating differential between teams becomes the basis of the opening spread. The vig is added to this fair line to create the book's priced market.
Who Moves First
In the US, recreational books like DraftKings and FanDuel sometimes wait to see where Pinnacle and other sharp books open before posting their own lines. This "follow the sharp book" approach reduces their risk of opening a dramatically mispriced line.
Pinnacle is often first to market because their model is sophisticated enough to be confident in their opening prices. They also accept higher limits early, which quickly attracts sharp money to correct any mispricing.
How Quickly Lines Correct
A meaningful mispricing in a major market (NFL spread or NBA game line) corrects within minutes to hours of posting. Professional bettors run their own models constantly and monitor new lines immediately when they post.
Less-watched markets — mid-major college football, minor props, obscure international sports — take longer to correct and may retain inefficiencies longer.
[Monitor line movement from opening to close with Oddible →]
