This matchup between the 49ers and Bears presents a strong case for Chicago +3.5, given San Francisco's recent struggles and Chicago's improved performance against the spread. The 49ers are on a three-game losing streak, highlighting their lack of momentum, and they’ve underperformed against expectations, covering the spread in just 4 of 12 games this season. Meanwhile, the Bears have a 7-4-1 ATS record, including a perfect 3-0 ATS as underdogs by 3.5 points or more, showing their ability to rise to the occasion in tougher matchups.

San Francisco's offense has been inconsistent, ranking 16th in the league with 22.5 points per game, which could limit their ability to pull away. On the other hand, Chicago's defense has been solid, allowing just 20 points in their last game against the Lions, which could help keep this contest competitive. Additionally, the Bears have shown resilience, keeping games close even in losses, including a narrow 23-20 defeat to Detroit in their most recent outing.

Divisional and conference games often trend towards tighter contests, favoring the underdog in situations like this. With Chicago's strong ATS performance and San Francisco's offensive and recent struggles, the Bears +3.5 offers solid value in this matchup.