49ers’ Studs and Duds: Defensive coordinator Steve Wilks is giving the Niners no chance to win

SANTA CLARA — We weren’t hallucinating: The 49ers really did start this season 5-0.

They really did look unbeatable in the process.

My, how things have changed in a few short weeks

The Niners will head into their bye week and the second half of the schedule carrying a three-game losing streak and nothing but bad vibes, sitting second in the NFC West.

Here are the studs and duds from the Niners’ 31-17 loss to the Bengals on Sunday. (You can probably skip the first part.)

STUDS

Arik ArmsteadThe defensive tackle had his first regular-season sack since the 2021 season Sunday. Then he picked up another one. What a time to be alive.

Brock Purdy, as a runnerPurdy ended Sunday’s game as the Niners’ leading rusher. He was pretty good with his feet.

That’s good, because his misses with his arm helped bury the Niners on Sunday.

George KittleKittle caught nine passes for 149 yards Sunday. That’s a big game for the tight end, even with two bad drops.

Brandon AiyukAside from a pass that hit him directly in the facemask, Aiyuk was money in this game, catching five passes (on nine targets) for 109 yards.

Jaylon MooreNo one can appreciably say it was his fault the Niners lost. That’s a win for him!

Christian McCaffreyIt was another two-touchdown game for the Niners’ running back, who is everything for this team right now. McCaffrey had 108 yards of total offense — an accomplishment behind this offensive line.,

DUDS

Brock Purdy the passerThere were a couple of really nice throws in this game.

Then there were two inexplicable, game-losing interceptions.

The first came at the Cincinnati 8-yard line at the end of the third quarter. Instead of rolling right and completing a little flip throw to Elijah Mitchell for a touchdown, Purdy put the ball into the hands of Bengals linebacker Germaine Pratt. At least three points came off the board with that play.

And then on Purdy’s next offensive play, he threw the ball directly to Bengals linebacker Logan Wilson. What he saw on that throw is beyond me — his intended receiver, Brandon Aiyuk, had a defender in front, behind, and to the sides of him. Quadruple coverage.

Purdy’s final turnover — a strip-sack fumble — only added insult to injury. The game had already been lost.

Steve WilksThe 49ers’ defensive coordinator’s playbook is a one-sheet. The Bengals, like the Vikings last week and the Browns the week before them, knew precisely what defense the 49ers were running every time they snapped the ball.

Joe Burrow completed 19 straight passes at the end of the first half — that’s no accident.

The Bengals had 20 first downs at the break, too. That’s a game’s worth of chain-moving plays. They finished with 29, but they moved the ball so effectively it came across as mercy.

Cincinnati made offense look easy because the Niners ran zone coverage with two high safeties on seemingly every single snap. I could call out the 49ers’ defense from the press box – of course Burrow had no problem carving it up on the field.

This 49ers’ defense has no ingenuity and is now devoid of aggression. It doesn’t matter how good the players are or aren’t if they’re predictable pylons to the opposition.

Wilks has given the Niners’ defense no chance to win.

Kyle ShanahanI hope you all enjoyed Christian McCaffrey this past year, because Shanahan is hellbent on running the running back into the ground.

This is an issue. The Niners were dramatically outcoached on Sunday. Shanahan’s offense is a shell of what it was with Deebo Samuel in the lineup. Some drop-off is to be expected when you lose a player like Samuel. This level of predictability is stunning.

He also called a run play in the final seconds of the first half with no timeouts remaining, ensuring that the Niners wouldn’t be able to run another play, much less kick a field goal down 14-10.

The 49ers have never won a game under Shanahan where they have trailed by 8-or-more in the fourth quarter.

Jauan JenningsIt was a horrendous blocking day for a wide receiver who had earned the reputation as one of the best blockers in the NFL. I partially blame Shanahan, who effectively used Jennings as a telegraph to the defense, telling them the Niners would be running.

Spencer Burford, Jake Brendel, Aaron BanksCall ‘em the “Killer B’s.” As in, the Niners’ two guards and center are killing their offense.

The Niners have been gashed up the middle for the last few weeks, and while Cincinnati isn’t a team to take full advantage of the situation, they still stopped the 49ers from being able to gain anything from interior runs. They also flushed Purdy out of the pocket, repeatedly.

Changes need to be made before the problem gets worse. It’s enough to torpedo a season.