Niners expect more from defense

NaVorro Bowman is 24 years old. Aldon Smith is 22. Ray McDonald and Patrick Willis are 27.
Vic Fangio referenced their ages Tuesday as a way of answering what quickly became the theme of his first press conference of the spring season: How does a 49ers defense that produced 38 turnovers, dominated against the run and ranked fourth overall in the NFL last season improve in 2012?
Said Fangio, the team’s defensive coordinator: “All our guys are either very obviously young or in their mid-20s in the middle of their career. We should be as good or better.”
The notable exception to that rule is Justin Smith, who will turn 33 in September.
Still, Smith had perhaps the finest season of his 12-year career in 2011 at the ripe old age of 32, and Fangio noted that the defensive end’s training regimen is so rigorous that he shows no sign of slowing down.
“I don’t see the end for him yet,” Fangio said. “And I mean looking forward two or three years. I think he’s still here and playing at a high level.”
Another reason for Fangios’ optimism lies in the man lining up next to Justin Smith on the right side of the 49ers’ defense.
Last year Aldon Smith set a franchise rookie record with 14 regular-season sacks and flirted with the NFL record for a rookie. He did so despite playing only 48 percent of the team’s defensive snaps.
Smith typically entered the game in passing situations where he lined up as a defensive end in a four-man front. His assignment: locate the quarterback and bring him to the ground.
This year, the only change to the 49ers starting defense is that Smith will replace Parys Haralson as a starter at right outside linebacker. Fangio estimated that Smith played about 20 to 30 snaps as an outside linebacker last season. Barring injuries, he could see close to 1,000 snaps at the position this season.
Fangio said the spring practices, such as this week’s minicamp, were especially valuable for a young player like Smith who didn’t have any formal practices last spring because of the lockout and who is lining up at a position he hardly played in 2011.
Fangio said Smith had to learn how to drop back into the backfield and master zone coverages, something that draft evaluators predicted he would have trouble doing when he was taken seventh overall in 2011.
He also must learn how to stop the run, the 49ers’ defensive strength last season.
“One thing Parys was really good at for us last year was playing the run,” Fangio said. “And (Smith) has to be as good or better than Parys was at playing the run.”
Smith said Haralson was an excellent mentor last season and continues to be one this year even though Smith has leapfrogged him on the depth chart.
“I get a lot of tips from him,” Smith said. “Just attack it – that mentality.”
As far as replicating 38 turnovers, Fangio acknowledged that takeaways can be capricious and that it’s possible the 49ers won’t have as many as they did last season.
But he also noted that they were steady producers when it came to turnovers in 2011.
“I don’t think we had a game where we had, like, six or seven of them,” he said. “We kind of had a lot of games where we got two, three, maybe four. So we were fairly consistent. There were only a couple of games where we didn’t get any.”
He’s right.
The only two regular-season games in which the 49ers failed to force a turnover were in a win against Detroit – a game in which they had a key safety – and a loss to Baltimore.
Of course, they also had no takeaways against the Giants in the NFC Championship game.