Once betting begins, sportsbooks can adjust the line at any time.
Individual books having players who consistently bet with certain tendencies (such as an extreme bias toward favorites or toward a certain popular team like USC)
Since the oddsmaker's ultimate goal is equally dividing the betting action, public perception and betting patterns must be taken into account.
"The main objective is that our clients get equal action on both sides," Seba said.
Power ratings are the oddsmaker's value of each team and are used as a guide to calculate a "preliminary" pointspread on an upcoming game.
Experts working for the individual books having a strong opinion on the game
Las Vegas Sports Consultants (LVSC) is the world's premier oddsmaking company and the most respected authority on making the lines. We do this by drawing from past experiences and applying them to current situations. In our extended interview, Seba explained that there are 4-5 oddsmakers assigned to make lines for each of the major sports (pro & college football and basketball; MLB, NHL, boxing, golf). By necessity their approach is very research-oriented and concise, since with millions of dollars at risk there is little margin for error. Stated another way, they want to create a line that half the people find appealing to bet one way while the other half find it appealing to bet the other way (known as 'dividing the action').
The last step in the line-making process for each oddsmaker is taking one final look to determine whether or not the line "feels right." This is where common sense and past experience with how games are bet enters into the picture. People think it's much more complicated, but it's not."
Why the Line Changes
There is a common misconception that point spreads represent the oddsmakers' prediction of how many points the favorite will win by. Obviously, if the line comes out a week ahead of the event (which is the case in football), there is much that could happen during the week leading up to the event that could affect the line.
Contributed by: . Seba explained that it all starts with each oddsmaker creating a line on each game based upon their own personal approach. In doing so they attempt to make more attractive the team that is getting less action. If an oddsmaker comes up with a preliminary line of USC -7, then an adjustment up to -7.5 or -8 would be made in response to the public's expected USC bias. That is not the case at all - their intent is NOT to evenly split the ATS result between the teams; rather, their goal is to attract equal betting action on both sides. By moving the line, sportsbooks can influence how the public bets on a particular game.
"The #1 thing for us is to make a line for each game that creates good two-way action.
The purpose of these adjustments, like all line adjustments, is to more equally divide the betting action. Mike Seba is a Senior Oddsmaker at LVSC and has been making lines for the last six years.
Oddsmakers at LVSC are professional sports junkies who love what they do and would probably do it for nothing if you asked them, but they do get paid for it.
Oddsmakers can also change the line depending on various event-related factors such as player injuries or weather. Examples of non-game factors that would require an adjustment to a team's power rating are key player injuries and player trades.
What Is the Line Trying to Accomplish?
Moving the line is the oddsmaker's effort to balance betting action, and often times such moves can have a major impact on a bettor's decision. For example, the public might have heavy betting interest week after week on a popular college football team such as USC. The power ratings are adjusted after each game a team plays. How the Opening Line Is Made
"You either have a passion for it or you don't," Seba said. Oddsmakers have to determine if any changes are necessary and send out an "adjusted line."
For example, if the pointspread on a game is 7 and most of the money is coming in on the underdog (taking the +7), sportsbooks will then move the number down to 6 ½ to try and attract money on the favorite.
A round-table discussion among the 4-5 oddsmakers involved in making the line for each sport is then conducted and a consensus line is decided upon by the Odds Director before it is released to the sportsbooks. "We're not trying to pick the team that covers the spread, we're trying to make it a coin flip, a tough decision (for the bettor). This usually includes having up-to-date power ratings on each team. Also, adjustments are made after reading each team's local newspapers to get a sense of what the coaches & players are thinking going into the game. Reasons for such adjustments include:
The opening line is the first line created by the oddsmakers, which is then sent out to sportsbooks. Each of these oddsmakers bring unique opinions, strengths and weaknesses to the process. Of the 4-5 oddsmakers, generally the 2 most respected opinions are weighed more heavily by the Odds Director before he decides on the final line.
Once a game's power rating based pointspread is determined, the oddsmaker will make adjustments to that line after considering each team's most recent games played and previous games played against that opponent. Of course there is an entire method to the madness on how the opening line is created.
Divided action means the sportsbook is guaranteed a profit on the game because of the fee charged to the bettor (called juice or vig - typically $11 bet to win $10). If we've done that, we've done our job."
Once the opening line is released by LVSC, the individual sportsbooks decide if they want to make any adjustments before offering it to the public