Many factors go into a point spread, including player news, recent game results, where the game is played, weather announcements, and injury news. Once a line is set, the point in sports spread betting often changes. The factors listed below could affect the point spread, but betting action is the main reason.
- Betting Action: Sportsbooks set a line hoping that half of the spread betting action goes to one side of the bet and half goes to the other side. If this happens, the sportsbook collects the vig and profits are assured. If a lot of action happens on one side of the bet, then the bookmaker moves the spread to encourage betting on the other side.
- Injury News: Important injury news also can change the line. In the NFL, if a quarterback gets injured during the week (or news emerges of an injury), then the point spread might change. Other key players might affect the spread, as well. In some cases, sportsbooks stop taking bets if an important player is declared “Out”.
- Weather News: Snow storms, torrential rain, and high winds can affect point spreads. The weather might affect one team more than another because of play style (passing team vs running team). As a rule, the weather tends to affect over/under betting a bit more than point spreads.
- Game Site: Home field advantage generally gives a team a +3 boost in NFL betting but this is a part of the original point spread. Game sites don’t change midweek that often, but a game between the Buffalo Bills and Cleveland Browns was moved to Detroit in the 2022 NFL season because of the weather.
- Player News: If a key player breaks team rules and is suspended for a game, that can change the point spread. The same can happen if the league office suspends a player for a game. Again, the player must be pivotal to the team’s success.