How accurate were the PFF grades for the 49ers defense in 2019?

We went over how PFF graded the San Francisco 49ers offense last week. Remember, as you read the grades from PFF below that “70” is considered average. Here is a brief explanation of how their grades work from their website:

On every play, a PFF analyst will grade each player on a scale of -2 to +2 according to what he did on the play.

At one end of the scale you have a catastrophic game-ending interception or pick-six from a quarterback and at the other a perfect deep bomb into a tight window in a critical game situation, with the middle of that scale being 0-graded, or ‘expected’ plays that are neither positive nor negative.

Let’s get into the positions on defense.

Defensive Line

Edge Rusher

Arik Armstead 89.8, Nick Bosa 86.7, Dee Ford 84.4

Ronald Blair III 77.5, Kentavius Street 50.6

The 49ers had three edge rushers in the top-20. Bosa and Armstead were in the top-16 for total pressures, and Ford likely would have cracked the list had he stayed healthy. There isn’t much to say about these three that hasn’t been said already. The 49ers will continue their historic 2019 if these three stay healthy. The defense is dangerous with two edge players on the field. When there’s three on the field, you ensure at least two players aren’t double-teamed. We saw a healthy defensive line destroy teams in 2019 because there is too much talent to single block the Niners edge rushers.

When Ford was on the field, the 49ers pressure rate was an absurd 38%, which was 10% higher than the first place Steelers. Bringing back, Blair was a no-brainer, considering how productive he was as a backup.

Defensive tackle

D.J. Jones 67.8, Solomon Thomas 56.7

Kerry Hyder 68, Jullian Taylor 67.9, Kevin Givens 45.7

This list is why the 49ers should draft a defensive tackle higher than most fans want to. DeForest Buckner graded as a 78 overall, and that was fair. I have a hard time believing that the defense will be “fine” without bringing in a capable body, which is why signing a veteran like Marcel Dareus makes too much sense.

As for the grades, Taylor and Jones being equals is a strong argument to stop citing PFF’s grades as gospel. Jones was excellent last year. If the 49ers can build his stamina, Jones has a chance to be one of the better one-techniques in football. He has the athleticism to play three-technique, but I’m not sure D.J. can hold up playing over 50 snaps each game.

Thomas and Hyder are ideal sub-package players. I liked that the team threw Givens to the wolves in the middle of the season to see what he can do. Givens is still a year or so away from producing. This unit needs to add talent.

Linebacker

Fred Warner 66.9, Dre Greenlaw 63.9, Kwon Alexander 61.3

Azeez Al-Shaair 42.1, Mark Nzeocha 45.8, Joe Walker 45.6

PFF puts too much emphasis on missed tackles, and that’s why these grades are all below average. Warner is not the 44th best LB in the NFL. Not in 2019, at least. More proof that every play isn’t being graded. As much credit as the defensive line got—deservedly so—the coverage from the linebackers may have been the most underrated aspect on the 49ers team last year. Not defense, team. All three of the starters made plays in coverage. It was the throws they took away that led to the quarterback holding the ball longer and, in turn, creating a poor decision that turned this defense around.

Speed and smarts were the biggest difference in 2019. I’ll take that trade-off for a couple of missed tackles every day of the week. The 49ers continued to get more athletic this offseason by adding Walker. We’re looking at one of the best linebacking corps in the league.

Cornerback

Richard Sherman 88.9, Emmanuel Moseley 70, K’Waun Williams 77.2

D.J. Reed 74.8, Ahkello Witherspoon, 61.3

In his role, K’Waun was great. The 49ers didn’t ask him to play much man-to-man, but Williams was such a good run defender and blitzer when called on. Sherman was PFF’s highest-graded coverage cornerback, and Moseley played well enough to start in 2020. All three played above expectations in 2019, but all three are unrestricted free agents after this season.

As is Spoon. I’ve asked myself, “what if” with Witherspoon once a week. Before the injury, the lightbulb came on. He was aggressive, confident, and making plays all over the field. We didn’t see the same assertiveness after an injury from Witherspoon, and his play got progressively worse at the end of the season, leaving the coaching staff no choice to bench him.

Safety

Jimmie Ward 84.2, Jaquiski Tartt 66.4

Tarvarius Moore 64.9, Marcell Harris 64.5

Tartt had a grade of 47 against Washington Week 7 and 29 against the Cardinals Week 9, so his grade took a hit. Tartt was well-above average in 2019. He was closer to Ward, who was also outstanding. We didn’t get a full season out of these two, but it was pretty close. Tartt and Ward have always had the talent, and we saw why the 49ers have been patient with the duo in 2019. The most surprising aspect of each of their games was their football intelligence. Ward would sniff out a route combination deep, while Tartt would see a run coming around the line of scrimmage. For what Robert Saleh asks of his defense, good luck finding two better fits at safety.

Moore and Harris did a nice job filling in off the bench. Moore showed promise as a starter, and when he came in during sub-packages as the third safety, Moore proved to be a difference-maker. I’d like to see Moore three-safety looks from the 49ers in 2020. The defense is at their best when 11 athletes are on the field, and they can overwhelm offenses with their speed.