19 things that went wrong for the 49ers in Week 18 against the Seahawks

There is nothing new to break down from the Seattle Seahawks side. They haven’t played anyone since we last saw them, which was only two weeks ago.

There is new information about the San Francisco 49ers. Some good: Fred Warner potentially returning this weekend and Ricky Pearsall feeling optimistic he’d play. Trent Williams’s upgrade to full shouldn’t be swept under the rug, either.

There is also some bad news: George Kittle tearing his Achilles. Kittle remains one of the most impactful players in the NFL, regardless of his position.

During the regular season, the 49ers averaged 4.1 yards per carry on designed runs with Kittle on the field, compared to 3.7 when he was off. The 49ers also had rushes of 10+ yard carries 7.3 percent of the time when Kittle was off the field, compared to 10.8 percent with Kittle on the field.

Last week, Kyle Shanahan drew up plays that involved Kittle beating All-Pro cornerback Quinyon Mitchell in 1-on-1 scenarios. In Week 18, one of the few things that went right for the 49ers was a big play to Kittle. He led all tight ends this season in receiving yards over expected at +156. Calling Kittle “good” is selling him short.

Speaking of things that didn’t go right for the 49ers in Week 18, we are going to go through 19 of those. There isn’t much you can hang your hat on offensively when you only muster three points in a game. Being limited to 42 plays and going 2-for-11 on third- and fourth-down conversions probably made it a difficult rewatch for the Niners.

Miscues on offense

Of those 19, eight are on offense. We will give credit to the Seahawks’ front 7. The 49ers didn’t have any negative rushes, but they had a slew of one, two, and three-yard gains. The 49ers’ offensive line was middle of the pack in Week 18, ranking 16th against Seattle in yards before contact. Even understanding Trent Williams’ impact, we’ll act as if the 49ers will struggle once more on the ground.

Let’s start with the offense, and see how variance might be on their side in the Divisional Round:

1. On the 49ers’ initial third down of the game, they needed to pick up three yards. There is a receiver on the roster who inherited a nickname for this down-and-distance. It doesn’t happen often, but Brock Purdy and Jauan Jennings weren’t on the same page. Purdy expected Jennings to run an out route. Jennings acted like he was going to, but instead ran a “return” route back to the inside. It was a bad time for the two not to be on the same page on a choice route.
2. On a 2nd & 8 play in the first quarter, Purdy ran into a sack. Purdy’s pocket climbing is a skill, but on this play, he didn’t recognize the matchup he had with his checkdown option.

Shanahan drew up a design for Christian McCaffrey to come out of the...