NFL Week 1: Winning Teams Perfect 9-0 Against the Spread Heading into Afternoon

Casual sports bettors often over think the spread each week when betting on the National Football League, as often times it's as simple as picking the straight-up winner.

The Green Bay Packers started the party with a 42-34 win as 4.5-point home favorites on Thursday night, keeping the New Orleans Saints out of the end zone with a goal-line stand.

Winning teams have covered the closing spread by an average of 15.5 points in the first nine Week 1 games heading into Sunday afternoon matchups.

It's a staggering statistic that is led by the Buffalo Bills' 41-7 win over the Kansas City Chiefs, providing a 38-point against-the-spread winner as four-point underdogs.

Home underdogs fared well, as the Chicago Bears (+2) and Jacksonville Jaguars (+1.5)—posting wins over the Atlanta Falcons and Tennessee Titans respectively. St. Louis (+3.5) failed to deliver in a 31-13 loss to the Philadelphia Eagles.

The Detroit Lions continue to gain notoriety in Las Vegas after finishing the preseason as the only team to finish with a perfect 4-0 ATS record, picking up a 27-20 win over the Tampa Bay Buccaneers as 1.5-point road underdogs.

A six-point line move due to Indianapolis Colts quarterback Peyton Manning's injury wasn't near enough, as the Houston Texans easily covered a nine-point spread in a 34-7 win at Reliant Stadium as nine-point favorites.

It's definitely a trend to continue monitoring during the afternoon games and leading into Sunday night's finale between the Dallas Cowboys and New York Jets at MetLife Stadium on NBC.