To describe the 49ers defense as simply good is like saying the Sistine Chapel has a decent painting on it’s ceiling. It doesn't quite fit. Consider this:
- • The 49ers defense has not allowed a 100-yard rusher in 20 consecutive home games or allowed a rushing touchdown in their last 10 games at home, currently the longest streaks in the NFL.
- • The defense had a Pro Bowl player at every level of their defense last season (DT Justin Smith, LB Patrick Willis, CB Carlos Rogers, S Dashon Goldson), not to mention LB NaVorro Bowman earned All Pro honors but was not invited to the Pro Bowl.
- • They led the league in run defense last year allowing opponents 77.2 yards per game on the ground. The second best defense against the run was the Ravens by more than 15 yards per game (92.6).
- • The 49ers allowed 14.3 points per game, second fewest in the NFL (Steelers 14.2), and more than two points fewer than third place Baltimore (16.6).
The 49ers have a great defense and it’s up to Lions quarterback 
“You know they don't do a ton which helps them play assignment sound and I think they have smart football players,” Stafford said. “They're coached well. Obviously you can see that when you watch the tape on them. And they have a lot of talent so they don't have to do a whole lot.”
The 49ers are the best example in the NFL of having personnel that fits a particular scheme. It’s something Lions head coach Jim Schwartz talks about all the time when finding players for his scheme.
“They have personnel that fit that very well,” he said Wednesday of the 49ers defense. “They have good pass rushers; they have guys that can eat space inside and that’s important in their scheme. They have outstanding linebackers. NaVorro Bowman, everybody knows Patrick Willis, but Bowman had a little bit of an under-the-radar year last year.
"They’re good at all three levels. Defensive line, linebacker, and they got a Pro Bowl safety that was their franchise player. Carlos Rodgers has done a really good job."
The 49ers run a base 3-4 defense and run an even front in the nickel. That’s it. There’s nothing real complicated about it. There’s no zone blitz scheme or anything exotic about it. They keep it simple and have talented -- yet disciplined -- players that know their roles and play them well.
“They're going to be at the right place at the right time,” Lions receiver
“With these guys you have that type of talent and they rarely make mistakes so you might see a gap, but somebody's filling it. Or you might see a blitz, but there's a player replacing it. So that's what makes them good. You rarely find them out of position.”
The 49ers had at least one player rank among the top-seven in the NFL last year in every major statistical category (tackles, sacks and interceptions).
In last year’s loss to the 49ers at Ford Field in Week 6, the Lions rushed for 66 yards and were 2-of-15 on third down (13-percent). Stafford had a decent game -- 293 passing yards and two touchdowns -- but did so under duress (five sacks and 11 quarterback hits).
“They’re good pass rushers, they’re good run stoppers, they’re opportunistic," Schwartz said. "We definitely have our work cut out for us.”
Lions guard
“It’s their best vs. our best,” Sims said. “We have respect for them and hopefully they have respect for us.”
