NEW ORLEANS — The New Orleans Saints suffered the most improbable loss of the season on Sunday, when they got steamrollered in their own Superdome 26-9 by the rival Atlanta Falcons.

It snapped a six-game winning streak for the Saints, who fell to 7-2. And it snapped a six-game losing streak for the Falcons, who are now 2-7.

How rare was the upset?

New Orleans was favored by 13.5 points,