How does Vegas know?
That’s the most popular question on social media whenever a game falls exactly on or near the spread. But the truth is oddsmakers don’t know and they aren’t nearly as accurate as they’re given credit for being.
For example, the NFL is by far the easiest league to create point spreads for. Double-digit lines are few and far between and very rarely will they be greater than 14 points. Yet, since 2002, nearly 60 percent of NFL games have been decided by more than seven points of the spread, according to Spreadapedia. More than 28 percent of NFL games have been decided by more than 14 points over the past 10 seasons. And only 5.5 percent of games have landed exactly on the closing point spread.
Even on those rare occasions when a final score does duplicate the point spread, oddsmakers don’t deserve all the credit. Bettors are more responsible for the closing lines than oddsmakers. In fact, after glancing at their power ratings, checking injury reports and spitting out a number designed, in most cases, to attract even action on both sides, oddsmakers’ jobs are pretty much done. It then becomes the bettors’ job to decide whether a team will beat another by a certain amount of points, thus shaping the line into its closing number.
Please keep this in mind as the NFL regular season kicks off this week, and refrain from writing tweets such as this one, from Saturday:
Let’s take a closer look at the NFL by the numbers over the last decade or so …
93 – The number of games since 2003 that have moved more than three points from the opening point spread at PinnacleSports, according to Bet Labs.
341 – The number of games since 2002 that have finished with a margin of victory of three points. (Complete chart of margin of victory)
22 – The number of times a 3.5-point favorite has won by three points since 2002.
8 – The number of times a 6.5-point favorite has won by seven points since 2002.
61.3 – The percentage of games Green Bay Packers coach Mike McCarthy has covered the spread in, the best ATS mark among active coaches with more than two seasons under their belt.
24.5 – The largest point spread of any NFL game since 1975. The New England Patriots were favored by 24.5 over the Philadelphia Eagles in Week 12 of the 2007 season.
1,463 – The number of underdogs to cover the spread since 2002.
1,415 – The number of favorites to cover the spread since 2002.
2,886 – The number of games to go OVER the total since 2002.
2,878 – The number of games to stay UNDER the total since 2002.
h/t to our friends at Spreadapedia for the statistical data used above and throughout this article.