The 49ers' secondary struggled mightily on Monday night, and their Pro Football Focus grades showed just how badly.
In their 34-24 loss to the Buffalo Bills, the 49ers allowed Josh Allen to complete 32 of his 40 pass attempts for 375 yards and four touchdowns. Safety Tarvarius Moore made his fourth start of the season, and Allen and his receivers feasted on Moore's mistakes.
Allen’s passer rating against Moore was a perfect 158.3. He completed all six attempts for 126 yards and two touchdowns to the receivers Moore covered. The safety allowed an average of 21 yards per reception.
Cornerback Jason Verrett had his most challenging game since taking over a starting role with the 49ers. He allowed eight receptions on 10 attempts for 85 yards, an average of 10.6 yards per reception. Verrett’s previous high allowed was 50 total yards in the 49ers' Week 9 loss to the Green Bay Packers.
Richard Sherman allowed three catches on three targets for 35 yards and a touchdown, the most he'd allowed in his three starts this season. Allen’s passer rating against the All-Pro cornerback was 154.9.
Defensive end Dion Jordan was the only 49er able to sack Allen. The quarterback had a clean pocket and a lot of time in the backfield for much of the game, getting pressured on just 10 of 43 dropbacks (23.3 percent) and hit on only three (7.0 percent). Allen was able to air it out as a result, completing all six of his throws 20-plus yards downfield for 159 total yards and two TDs.
Missed tackles were among the 49ers' biggest mistakes. Sherman, Verrett, Dontae Johnson, Kerry Hyder and Dre Greenlaw each missed at least one tackle.
Here's what else stood out from the 49ers' performance, courtesy of Pro Football Focus.
OL Laken Tomlinson: He scored a 90.1 overall grade, which is the highest of any guard in the NFL so far in Week 13. Tomlinson has not allowed a quarterback pressure in two consecutive games.
TE Charlie Woerner: He received an 86.0 overall grade in 15 snaps. His first two career receptions were for 33 yards, gaining 26 after the catch.
TE Ross Dwelley: He earned an 85.3 overall grade with two catches for 28 yards, both of which were for first downs.
OL Colton McKivitz: The rookie lineman struggled and received a 22.9 pass-blocking grade, allowing four quarterback pressures (one hit, three hurries) in 20 pass-blocking snaps.
LB Fred Warner: He scored an 89.7 overall grade, which was highest on the 49ers' defense. Warner's 84.3 overall grade on the season is second best among linebackers, just behind Bobby Wagner (84.5).
DB Dontae Johnson: He scored an 85.0 overall grade in his second start for the 49ers. He allowed five catches on six targets for 34 yards, and had one pass breakup as well as two stops in the run game.