Win the turnover battle
It's nearly impossible to stop a San Francisco offense averaging 28.9 points per game. The 49ers have so many star players they can lean on. And with Kyle Shanahan calling the plays, it's almost unfair on opposing defenses.
The way to win? Force turnovers. Again, this is how the Packers won games as underdogs this season. They took the ball away three times against the Lions, once against the Chiefs, and twice against the Cowboys.
Not including Week 18, when they rested most of their starters, the 49ers have lost four games this season. They had at least one turnover in each loss. In three of those defeats, they gave the ball away at least three times.
The rain could play a role on Saturday night, making ball security a challenge. Brock Purdy threw an interception and fumbled (which he recovered) in similar conditions against the Cleveland Browns this season.
But the Packers can't rely on the rain to help them force turnovers. That works both ways. They must win by disrupting Purdy's timing, which the Baltimore Ravens did well, leading to four interceptions. Replicating what Baltimore's dominant defense achieved is easier said than done, but Green Bay's pass rush can be relentless when at its best.
It's hard to see a path to victory for the Packers if they don't win the turnover battle. The defense must get takeaways.