The San Francisco 49ers looked ready to give the Detroit Lions a nice little fight in the first half on Sunday, with the offense jumping out to a solid start. The defense had its struggles in the first half, jumping offsides in some form or fashion six different times. They finished with seven such penalties. I did not include them in player stats, and we'll take a look at them separately.
And yet, they also had some solid moments, and the game was competitive through the first half (the magic word!). Things went south though, and the 49ers could not get back into it as the second half wore one. As always, the snap count does not reveal everything, but we can make some pretty specific inferences based on it. I thought we would start by looking at the defensive side of the ball (Gamebook PDF).
Defensive Line
| Pos | Player | Plays | % | Stats |
| DT | Ian Williams |
45 | 63% | 5 tackles, 1 assist, 1 pass defense |
| DT | Mike Purcell |
37 |
52% | 2 tackles, |
| DT | Quinton Dial |
30 |
42% | 1 tackle, 3 assists, 1 QB hit |
| DT | Tony Jerod-Eddie |
25 |
35% | 3 tackles, 1 assist |
| DT | Arik Armstead | 22 |
31% | 2 tackles |
| DT | Tony Jerod-Eddie | 17 |
24% | 3 tackles, 1 assist |
The 49ers did solid work against the run, holding the Lions to 87 yards on 28 carries. Of course, the Lions are not built to be a running team. The 49ers struggled getting much pressure on Matthew Stafford, with Arik Armstead and Tank Carradine both failing to secure a QB pressure. Ian Williams continues to play some really strong football. His free agency is going to be interesting, to say the least.
Outside Linebackers
| Pos | Player | Plays | % | Stats |
| OLB | Aaron Lynch | 54 | 76% | 1 assist |
| OLB | Ahmad Brooks |
49 | 69% | 1 tackle, 2 assists, 1.5 sacks, 1 tackle for loss, 2 QB hits |
| OLB | Eli Harold |
22 | 31% | 1 assist, 1 QB hit |
Ahmad Brooks quite the day, getting some decent pressure on Stafford. Eli Harold got a hit as well. The "good news" would be that Aaron Lynch came back and got plenty of work in. He missed two games with a concussion, so getting him on the field was a big plus/
Inside Linebackers
| Pos | Player | Plays | % | Stats |
| ILB | NaVorro Bowman | 71 | 100% | 8 tackles, 2 assists, 0.5 sacks, 1 QB hit |
| ILB | Gerald Hodges |
60 | 85% | 5 tackles, 4 assists |
Another busy day for the inside linebackers. NaVorro Bowman continues to get every snap, and is now the NFL leader in tackles. While tackles are not a great measuring stick (Derek Smith had a whole bunch on a bad 49ers defense), it is good for purposes of recognizing Bowman's continued return from his knee injury.
Cornerbacks
| Pos | Player | Plays | % | Stats |
| CB | Dontae Johnson | 70 | 99% | 3 tackles, 1 pass defense, 4 recs (5 tgts) for 63 yards, 1 TD |
| CB | Tramaine Brock | 68 | 96% | 3 tackles, 1 pass defense, 2 recs (3 tgts) for 7 yards, 1 TD |
| CB | Jimmie Ward |
55 |
77% | 2 tackles |
| CB | Kenneth Acker | 11 | 15% | 1 tackle, 2 recs (2 tgts) for 30 yards |
| CB | Marcus Cromartie | 3 | 4% | 0 recs (1 tgt) |
The gamebook lists Jimmie Ward as the second starting cornerback for some reason, but Dontae Johnson got the work. This is Johnson's second straight week getting the bulk of the snaps opposite Tramaine Brock. I suspect it continues in Week 17, but who knows with this coaching staff.
Safeties
| Pos | Player | Plays | % | Stats |
| S | Eric Reid | 71 | 100% | 5 tackles, 1 assist, 3 missed tackles |
| S | Jaquiski Tartt |
71 | 100% | 3 tackles, 3 missed tackles |
Another busy day for the safeties, and Jaquiski Tartt continues to struggle with missed tackles. We'll break down more of his work this offseason, but since moving into the starting lineup in Week 8, Pro Football Focus has marked him down for 12 missed tackles. They say that is tied for the league lead among safeties.