49ers defense: A deep dive into perception vs. reality of Week 1 against the Seahawks

Watching a game, a fan gets certain impressions. Sometimes, those impressions are obvious and accurate. Tight end George Kittle was dominant until he suffered an injury. Jake Moody was atrocious, and it had nothing to do with an injury.

Other impressions, however, can be more nuanced. Robert Saleh clearly had a substantial effect on the defense, but while the stat sheet looks very good, and the points allowed (the stat that really matters) was excellent, how dominant was the defense actually? I do not want to be negative, but it bears examination.

The run defense

The final tally was that the defense allowed only 84 yards on 26 carries, for 3.2 yards per carry. That is outstanding. On the other hand, the Seahawks' 69-yard touchdown drive had two passes (one that resulted in pass interference) and nine runs (6 yards, 5 yards, 5 yards, 4 yards, 2 yards, 4 yards, 4 yards, -1 yard, and a 1-yard touchdown run). Taken as a group, that's 30 yards on nine carries—a pitiful 3.3 yards per carry.

However, when you realize there was only one negative play, and the other carry for short yardage was a touchdown, the yards per carry was actually 4.3. That's not all that good. My eyes told me Seattle was running up the middle with no problem.

On their second field goal drive, an eight-play, 34-yard drive, the Seahawks passed once for six yards. The runs: 8 yards, 5 yards, 5 yards, 7 yards, 4 yards, and -1 yard. After the pass that left them at 4th-and-1, announcer Greg Olsen wondered why they did not go for it. They had been averaging 4.6 yards per carry on the preceding six runs, and without the one negative play, it was actually 5.8. I wondered the same thing and breathed a very long sigh of relief when they lined up for the field goal attempt, since a field goal meant a touchdown would give the 49ers the lead rather than a tie.

On the drives when the defense forced a punt, most of the plays that the Seahawks called were passes, with only a run or two thrown in.

What this tells me is that this run defense is not—right now—a lot better than last year's. Linebacker Dee Winters is much improved, but the defensive tackles, Jordan Elliot and Kalia Davis, were anything but stout up front. CJ West was the 49ers' most disruptive defensive tackle in his 26 preseason snaps, playing against the opponents' starters. I would like to see more of him.

The pass defense

It was clear the Seahawks wanted to go after rookie slot corner Upton Stout, and they had some success doing so. That said, until their final drive, quarterback Sam Darnold only completed three passes over 10 yards. Most of his connections were checkdowns. That means the corners—even Stout—had pretty good coverage downfield for much of the game. And except for some boneheaded post-play penalties, I do not recall cornerback Deommodore Lenoir's name being called. They just didn't throw his way.

Cornerback Renardo Green made some excellent plays. Rookie safety Marques Sigle had six tackles. While this unit is very young with its two rookies and one second-year man among the five, the back end shows a lot of promise. Sure, Stout struggled at times, but he is a rookie who missed all of the preseason games and a good chunk of training camp. He will improve.

It was wonderful to get the win, and especially to end it with a forced fumble, and especially-especially against Seattle and the obnoxious "12th man." And it is beautiful to have Robert Saleh back. As fans hoped, he certainly made a difference. But the 49ers have some growth to make on defense, especially against the run. Winters has made huge strides and looks like a legit starter. But I want those defensive tackles to step up. General Manager John Lynch drafted two to make a difference, and in the first game, they hardly saw the field.

Still, let's relax and take a deep breath (with Jake Moody only making a cameo in this article). The first game is behind them; there are 16 more to go. And there's a lot to be positive about.