The San Francisco 49ers unveiled their new-look defense last Sunday against the Carolina Panthers, and as expected, we saw some extensive rotation in the front seven. Defensive coordinator Robert Saleh has repeatedly mentioned the plan is to use whatever rotation they can to keep players fresh, and we saw it on Sunday.
The NFL has a stats service that provides a breakdown of lineup combinations, detailing the different variations a team uses on both sides of the ball. It’s great in terms of seeing how a team uses various formations, but the downside is how they accumulate the data. They will list out a given personnel grouping, but each week, they simply add to the total rather than providing a breakdown for each week. So, if 11 players appear in a given unit 10 times this week and 5 times next week, it will list it as 15, as opposed to splitting it up based on the given week.
With that in mind, we can at least use Week 1 to see exactly what personnel groupings the 49ers used. I’ll try and sort out ways to assess it week-by-week moving forward, but that is still TBD.
I’ve included a table below listing out the 26 different defensive formations the 49ers used against the Carolina Panthers. For a lot of these groupings, we can make a strong educated guess as to whether it’s base defense, nickel defense, or dime defense. However, without comparing to film, we can’t say it with absolute certainty. Additionally, I have not double-checked which of the tackles was on the right or the left in a given formation. It was meant more just to give us some idea of the players out there.
The most frequent formation was the base defense after Reuben Foster hurt his ankle. And in fact, three of the top four were base, as the 49ers spent 57 percent of their snaps in that. What is noteworthy is that Dekoda Watson was rotated in a decent amount in place of Eli Harold. Watson played 15 defensive snaps on Sunday. Eight of them were in base, and then it appears six were in dime, and one was in nickel.
The 49ers had 12 snaps that included Lorenzo Jerome. In all 12, he was on the field with Jaquiski Tartt in what appears to be a dime formation. We saw that in preseason Week 3 when Tartt moved into the starting lineup at free safety, and it appears that is the plan for the time being. I am curious to see how that changes when Jimmie Ward is back in action.
There are a lot of interesting little formation decisions that will be worth tracking in coming weeks. For example, defensive lineman Xavier Cooper, claimed off waivers after roster cuts, got 12 snaps on Sunday. In all but two of them, he was paired with rookie defensive tackle D.J. Jones. The other two saw him with Earl Mitchell. It seems like for the time being, Cooper is the primary backup to Buckner, while Jones is the primary backup to Mitchell.
Here’s the full rundown of personnel groupings. Anything jump out at you?
Week 1 defensive personnel groupings