I just put down $20 on today's game for the New York Giants to cover the 12-point spread. Of course, knowing me, I got to thinking how that betting line is decided. Is there one person who calculates the spread? Do Las Vegas casinos just put up numbers based on past experiences? I did a little bit of research, and here's what I found.
An Oddsmaker Defines the Line
To start things off, an oddsmaker, most likely from Las Vegas Sports Consultants, will look at past performances, read local news, and keep track of injuries. The oddsmaker makes a decision based on this information.
A common misconception about the betting line is that it is a prediction of how much a team will win by. This is not the case. A line is created to attract an equal amount of betting from both sides. A 50-50 split guarantees that the sportsbook will make money since they charge a betting fee. For example, I bet $20 to win $18.50.
Betting Line is Adjusted
The oddsmaker releases the odds and the sportsbooks are free to adjust before they put the lines up to the betters. When betting begins, the line can continue to change and get adjusted to achieve that 50-50 split among betters.
Let the Games Begin
When the game begins, the lines are set, and the betting stops.
So I've got my beer, chips, chili, cheese, and fried products all ready to go with betting ticket in hand. Go Giants! Who do you think is going to win Super Bowl XLII?
UPDATE: Woo hoo! The Giants win and I'm up 20 bucks.