Following up on 49ers' third-down defense

2011 49ers 3rd-down Nickel D vs. Giants

The "Final Word" item for Week 6 led with a look at how the San Francisco 49ers' third-down nickel defense fared against the New York Giants during two matchups last season.

I initially failed to account for how much the 49ers improved from the first to second meeting. That has been rectified. To drive home the point, I've put together a chart breaking out the numbers from the Week 10 matchup and NFC Championship Game.

Whereas the Giants were pretty consistently successful in those matchups during the regular season, they had a harder time dealing with the 49ers' pressure in the rematch. But they still gained seven first downs, averaged 7.2 yards per pass attempt and threw for a touchdown.

2012 3rd-down Nickel/Dime Situations

The second chart shows how the 2012 Giants' third-down offense has fared against defenses featuring additional defensive backs. It also shows how the 49ers' corresponding defenses have fared through Week 5.

The 49ers' sack total (four) in these pass-oriented situations seems low, but the 2011 version had only one additional sack on about the same number of pass plays through Week 5 last season.

"Teams have thrown the ball quickly on us at times," 49ers defensive coordinator Vic Fangio told reporters this week. "I haven't felt during any of the games like, 'Damn, where's our pass rush?' And until I feel that, then we don’t have a problem.

"Sacks are good. It's a number that fans and you guys can sink your teeth into, but it's not the only thing. Pressure is critical, causing incompletions, altering throws. On the interception that [CB Chris] Culliver got last week against Buffalo, that was a direct result of a really good rush by Ahmad Brooks. He doesn’t get credited for a sack for that. I like the interception better than the sack."

Teams applying pressure consistently tend to finish with lots of sacks over time. That makes sacks a good indicator, but it's important to see the fuller picture, as Fangio indicated.

The Culliver interception came on a first-down play.