1. Week Nine Vikings-31 Falcons-28
Before turning to Arthur Smith, the Falcons defense deserves a lot of criticism here. This was the best game of Josh Dobbs' career running around as if he were Cam Newton while throwing dimes in the second half, moving the ball at will. Dobbs wasn't the quarterback the Falcons prepared for but there is zero reason this roster should have put up the points as easily as they did.
This arguably started Smith's inability to close games against bad teams during the season. Though the previous week against Will Levis and the Titans qualifies this was the first game that approached "must win" level.
Smith had zero answers at the end of the game and the Falcons made Dobbs look like a top-five quarterback in the league. This is the game that really was the start of the end of Smith's tenure in Atlanta. All coaches lose games they shouldn't at times, however, what defines a good coach is their ability to bounce back and put the season back on track. After losing to the Titans the previous week Smith needed this game and was unable to find a way to respond losing his second straight in ugly fashion.