49ers Offense vs Seahawks Defense: Week 18 Execution Breakdown
In a crucial Week 18 matchup, the 49ers offense struggled to find rhythm against the Seahawks defense, falling 13–3. Despite strong performances from Brock Purdy and Christian McCaffrey, Seattle's suffocating coverage and pass rush shut down San Francisco’s attack, marking a pivotal loss heading into the playoffs.
Week 18 — January 3, 2026
Santa Clara, CA • Levi’s Stadium
Final Score: Seahawks 13, 49ers 3
In the wake of the 13–3 loss to the Seahawks on January 3, 2026, the PFF grades reflect a game dictated almost entirely by defensive execution. Seattle’s coverage unit and interior pass rush overwhelmed a short-handed and struggling 49ers offensive line, limiting San Francisco to just 4.1 yards per play and nine total first downs.
49ERS OFFENSIVE SNAP COUNTS & PFF GRADES (PFR + PFF)
| Player | Pos | Snaps | Snap % | PFF Grade | Notes |
|---|---|---|---|---|---|
| Dominick Puni | RG | 42 | 100% | 84.0 | 87.9 pass-block grade; 0 pressures allowed |
| Brock Purdy | QB | 42 | 100% | 76.2 | Game-high 77.9 rushing grade |
| George Kittle | TE | 40 | 95% | 64.4 | Led pass-catchers (66.1 receiving) |
| Jauan Jennings | WR | 37 | 88% | 64.4 | 4 receptions, 35 yards |
| Demarcus Robinson | WR | 37 | 88% | 58.1 | Heavy usage, minimal impact |
| Christian McCaffrey | RB | 36 | 86% | 56.0 | Season-low 51.1 receiving grade; 1 drop |
| Jake Brendel | C | 42 | 100% | 53.4 | 3 pressures, 1 sack allowed |
| Kendrick Bourne | WR | 22 | 52% | 52.0 | Limited involvement |
| Kyle Juszczyk | FB | 19 | 45% | 51.2 | Used primarily in pass protection |
| Colton McKivitz | RT | 42 | 100% | 48.8 | Tied team-high 4 pressures allowed |
| Spencer Burford | LG | 42 | 100% | 47.6 | 4 pressures; run-block issues |
| Austen Pleasants | LT | 42 | 100% | 38.7 | Lowest-graded offensive player |
| Player | Pos | Snaps | Snap % | PFF Grade | Notes |
|---|---|---|---|---|---|
| Nick Emmanwori | S | 42 | 100% | 78.4 | Led team with 7 tackles; 1 TFL; full-time box safety |
| Julian Love | S | 42 | 100% | — | Primary deep safety; avoided explosive plays |
| Ernest Jones IV | LB | 42 | 100% | 62.0 | 5 tackles; frequently spied Christian McCaffrey |
| Devon Witherspoon | CB | 42 | 100% | 74.1 | Allowed 0 catches on 3 targets; 2 PBUs |
| Tykee Okada | S | 42 | 100% | 58.9 | 3 solo tackles filling in for Julian Love |
| Drake Thomas | LB | 30 | 71% | 92.1 | Game-sealing INT; elite 90.1 coverage grade |
| Byron Murphy II | DT | 30 | 71% | 71.5 | 3 pressures; team-best 74.2 run-defense grade inside |
| Leonard Williams | DT | 29 | 69% | 56.6 | Lowest-graded starter; struggled holding run gaps |
| Riq Woolen | CB | 28 | 67% | 65.4 | 1 TFL; solid in man coverage |
| DeMarcus Lawrence | EDGE | 26 | 62% | 82.1 | 2nd-best defensive grade; 1 QB hit, consistent pressure |
| Josh Jobe | CB | 25 | 60% | 60.3 | Rotational corner; red-zone pass breakup |
| Uchenna Nwosu | EDGE | 23 | 55% | 72.8 | 1 sack; 3 hurries in limited snaps |
| Derick Hall | EDGE | 21 | 50% | 83.4 | Team-high pass-rush grade; 1 sack, 2 QB hits |
| Jarran Reed | DT | 17 | 40% | 68.7 | 1 sack; 1 TFL anchoring sub-packages |
| Boye Mafe | EDGE | 16 | 38% | 69.8 | Forced errant throw leading to interception |
| Rylie Mills | DE | 3 | 7% | 56.6 | Limited short-yardage usage |
OFFENSE VS DEFENSE — KEY MATCHUP TAKEAWAYS
The Coverage Clamp
Between Drake Thomas (92.1 PFF) and Devon Witherspoon, Seattle erased the intermediate passing game. Brock Purdy averaged a season-low 4.0 yards per attempt, repeatedly forced to check down or throw away.
Edge & Interior Pressure
Seattle generated pressure from every level. Derick Hall and DeMarcus Lawrence combined for seven pressures, while interior defenders collapsed the pocket early, preventing play development.
Neutralizing Christian McCaffrey
Seattle achieved what few defenses have managed — holding McCaffrey to zero forced missed tackles. PFF credited the Seahawks with an 83rd-percentile EPA per rush defense for the game.
Defensive Swarm Mentality
Despite a few lower individual grades, Seattle functioned as a cohesive unit, allowing only nine first downs and suffocating the 49ers on early downs.
FINAL TAKEAWAY
This was not a game lost by scheme or effort, but by execution at the line of scrimmage. Seattle’s defense dominated leverage, spacing, and pressure lanes, while the 49ers offense had no answers once protection failed.
BLOGGER LABELS
49ers Offense, Seahawks Defense, Week 18, Brock Purdy, Christian McCaffrey, Dominick Puni, Offensive Line, PFF Grades, NFL Film Review, 49ers Faithful
LABELS
49ers, Seahawks, Week 18, Purdy, CMC, 49ers offense, Seahawks defense, PFF grades, McCaffrey, 49ers playoff, Seahawks defense performance, 49ers struggles, NFL 2025, Purdy vs Seahawks, McCaffrey vs defense, 49ers loss, offensive line issues, Purdy 13, CMC struggles, 49ers game recap
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