Sunday Night Football features a blockbuster NFC showdown between the Green Bay Packers and Atlanta Falcons.

There's already been plenty of line movement. The Falcons are 3-point home favorites inside the new Mercedes-Benz Stadium, meaning Vegas thinks they'll win by a field goal. The line opened at Falcons -1.

The Over-Under, or total number of points Vegas thinks will be scored, stands at 54, down a half-point from where it opened.

Before you make any bets on Falcons-Packers, you'll want to hear what SportsLine Senior Analyst Larry Hartstein has to say.

Last week, he faded the Falcons as seven-point favorites at Soldier Field. The result: the Bears covered and nearly won outright. It was Hartstein's eighth straight win picking for or against the Falcons.

Part of his success: Hartstein was a sportswriter based in Atlanta for 15 years. He has his pulse on the Falcons.

He's going for nine Falcons picks in a row on Sunday Night Football, and he's sharing his pick over at SportsLine.

Hartstein knows these two teams met in last season's NFC title game at the Georgia Dome and the Falcons easily covered as 6.5-point favorites. They won by 23, but that doesn't mean lightning strikes twice, especially in prime time against Packers QB Aaron Rodgers.

The Packers handled the Seahawks in Week 1, covering the spread and holding Russell Wilson to 158 yards and a completion percentage barely above 50. Rodgers had more passing yards (311) than the Seahawks had total yards (225) and the Packers' defense owned Seattle's offensive line, sacking Wilson three times.

The Falcons, meanwhile, barely squeaked by an inferior Bears team. Atlanta's ground game was stymied for 64 yards and Bears QB Mike Glennon nearly led his team to victory despite a passer rating of 32.3. Falcons star wide receiver Julio Jones was limited to four catches for 66 yards.

Hartstein is leaning toward the Over on Sunday Night Football, but what about the spread, which he's made his name picking?

He knows there's a huge x-factor that ultimately determines the point spread winner for Packers-Falcons. And he's sharing it over at SportsLine.

So which side should you back in Packers-Falcons on Sunday Night Football? Visit SportsLine now to see what big x-factor determines which side you need to be all over, all from the expert who has nailed the last eight Falcons games, and find out.