The versatile wide receiver said Friday that curiosity has simmered from his defensive teammates about how opponents scheme against the unit since he joined the 49ers this offseason. And nobody in practice might know better than Boldin, who caught six passes for 104 yards and a touchdown to help the Baltimore Ravens beat San Francisco 34-31 in the Super Bowl.
"A lot of guys came up to me and asked me, 'What did the scouting report have on it? What did it say'" Boldin said. "Things like that. I've had a chance to communicate that to guys."
While he's not going to make those schemes public knowledge, Boldin has passed along that information to teammates while doing his own job catching passes from Colin Kaepernick. Picking Boldin's brain for ideas is just one of many ways the 49ers' defense -- among the NFL's best the past two seasons -- is trying to improve from within.
After all, San Francisco has almost everybody back on defense again. That continuity helps build upon past success, but it also allows little opportunity to improve -- other than from within.
"When you've done it so many times and you're OK at a lot of positions, we try to find little nitpicky things to get better on," cornerback Carlos Rogers said.
The departures of All-Pro safety Dashon Goldson and nose tackle Isaac Sopoaga left the most glaring vacancies to fill among the starting unit. At the other nine positions, San Francisco still seems stacked.
The 49ers ranked third in total defense (294.4 yards), fourth in yards rushing allowed (94.2) and fourth in yards passing allowed (200.2) per game last season. The unit still had flaws, though, most notably going from No. 1 in takeaways (38) in 2011 to No. 6 (25) in the league last season.
Defensive coordinator Vic Fangio spent time with players this summer reviewing what went wrong, particularly late in the year and in the playoffs, when the 49ers fell behind far too often and failed to create turnovers at the same rate. He also outlined what they could improve upon this season, pushing players who are highly decorated by pointing out the one accolade they're still missing: a Super Bowl title.
"We have guys who are willing to learn and willing to hear any type of critique from your peers, and I think that makes us a better team," All-Pro linebacker NaVorro Bowman said. "We have an ultimate goal to reach, and that's the greatest thing about it. We're all working so hard to reach that ultimate goal."
Among Fangio's points of emphasis was for players to practice the same technique and team principles in big moments -- especially against elite talent such as Green Bay, Atlanta and Baltimore, which all had success against them in the playoffs -- that carried the defense to consecutive NFC championship games and the Super Bowl last season.
The other is to build some much-needed depth behind the starters, who play as many minutes as any in the NFL. That lack of depth was particularly evident when lineman Justin Smith missed the final 2½ games of the regular season with a partially torn left triceps and was somewhat limited during the playoffs.
"It's an area of concern," Fangio said.
The loudest sounding board for the defense besides Fangio has been Boldin. The savvy wide receiver, who has described himself as quiet and reserved most of the time in his new surroundings, has been more than willing to help.
One of the tidbits Boldin revealed publicly about scheming against the 49ers is that the Ravens were particularly concerned about how much talent San Francisco had throughout its defense -- that there wasn't just one or two players to scheme against. Baltimore spread the 49ers out, particularly in the first half, allowing Boldin to run through pockets over the middle and forcing Bowman and fellow All-Pro linebacker Patrick Willis to chase faster receivers and tight ends.
The benefits have gone both ways.
Boldin said he's also taking advantage of going against such a strong 49ers defense every day. He called the challenge "the same" as facing Baltimore's vaunted unit the past three years in practice.
"You want a challenge every day," Boldin said. "You want guys that are going to make you work because in the end that makes you better as an offense. Offensively, here, we don't have any days off going against this defense. They have a lot of studs on the other side of the ball, and I think that's a plus for us."