How PFF graded Purdy, 49ers in demoralizing Week 13 loss to Bills

The 49ers' 2024 collapse continued with their 35-10 loss to the Buffalo Bills on Sunday at Highmark Stadium, and the team’s PFF grades reflect the lopsided score.

There were a few bright spots, however, that might give the 49ers Faithful hope that the long-term future remains bright. Some of San Francisco's young players stepped up in the wintry, snow-filled game that made footing and visibility a challenge.

Just when Christian McCaffrey and coach Kyle Shanahan’s run game appeared to be taking off, the All-Pro running back sustained a significant knee injury that might have ended his season. Jordan Mason took over and found the soft spot in the Bills' stout defensive line, but it wasn’t enough to keep up with the home team in the long run.

The elements clearly played their part in Brock Purdy’s efficiency. The 49ers quarterback was limited to 11 completions on his 18 pass attempts for 94 yards with a fumble. Both fullback Kyle Juszczyk and wide receiver Deebo Samuel also had trouble holding on to the ball, and San Francisco's three total turnovers helped Buffalo take an insurmountable lead.

Here are the 49ers' PFF grades from Week 13:

Offense

RB Christian McCaffrey — 76.9

Before leaving the game with a knee injury, McCaffrey resembled his old self with seven carries for 53 yards -- 29 of which came after contact. The reigning NFL Offensive Player of the Year also caught two of his three targets for 14 yards, all while only being on the field for 12 offensive plays.

RB Jordan Mason — 71.4

The third-year running back took over after McCaffrey left the game and kept the 49ers' ground attack moving. Mason carried the ball 13 times for 78 yards with a whopping 61 yards coming after contact.

QB Brock Purdy — 46.4

Purdy received his lowest grade of the season and the second-lowest of his NFL career. His lowest grade ever came during Week 6 of the 2023 NFL season in San Francisco's loss to the Cleveland Browns, when the quarterback’s overall grade was 44.1.

Purdy struggled in the elements Sunday, with less than 100 yards passing and his lowest depth of target average for the season at 5.2 yards per attempt. The quarterback’s fumble at the beginning of the fourth quarter was the primary reason for the low grade.

Offensive line

The group played well considering both left tackle Trent Williams (ankle) and left guard Aaron Banks (concussion) were sidelined for the game. The offensive line only allowed two pressures the entire game, both hurries, by Jaylon Moore and Ben Bartch. The group also was pivotal in creating lanes for the running game, which finally opened up Sunday night.

LT Jaylon Moore — 76.1 overall, 73.7 run blocking, 75.3 pass blocking

LG Ben Bartch — 78.4 overall, 76.5 run blocking, 67.7 pass blocking

C Jake Brendel — 67.6 overall, 63.7 run blocking, 81.4 pass blocking

RG Dominick Puni — 89.3 overall (top grade on offense), 77.9 pass blocking

RT Colton McKivitz — 60.3 overall, 51.7 run blocking, 76.6 pass blocking

Defense

The footing made it look like players were slipping due to a lack of traction on the turf, but the 49ers only were charged with six missed tackles, which is a huge improvement over 19 in their Week 12 loss to the Green Bay Packers.

Missed tackles:

S Malik Mustapha - 2

S Ji’Ayir Brown - 2

LB Dee Winters - 1

LB Fred Warner - 1

Defensive line:

Quarterback pressures:

Maliek Collins - Two hurries

Evan Anderson - One hit

Sam Okuainonu - One hurry

Kalia Davia - One hurry

Run defense:

DL Evan Anderson - 83.1

The rookie’s overall grade was the best on defense, with his team-high 84.2 run defense grade raising the average. Anderson registered four tackles -- three solo -- and three stops over 33 plays.

LB De’Vondre Campbell - 75.5

The linebacker registered five tackles — four solo -- with one stop and was not targeted during the game. Campbell was on the field for 41 defensive plays, or 71 percent.

Coverage:

The 49ers' secondary had a tough day, with safety Malik Mustapha recording the highest grade for coverage at 68.5. Bills quarterback Josh Allen completed 13 of his 17 attempts for 148 yards and two touchdowns.

CB Renardo Green — 61.0

The rookie cornerback made six solo tackles (none missed) and one pass breakup but allowed six catches on seven targets for 53 yards.

CB Charvarius Ward — 41.3

Ward’s return to the field was challenging, with the cornerback allowing two completions for 46 yards -- one for a touchdown. The All-Pro did receive an 80.2 grade for tackling, which was the top grade on the defense.

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