SANTA CLARA, Calif. - San Francisco 49ers defensive coordinator Vic Fangio has coached two of the greatest linebacking crews in NFL history.
Which one is better could be determined by what happens in the Super Bowl, when the 49ers linebackers will face maybe the biggest test of their careers - stopping the Baltimore Ravens' running game on the sport's biggest stage.
The focal point of what is expected to be a bone-jarring, head-rattling matchup is the Ravens' 260-pound fullback Vonta Leach, who opens holes for running back Ray Rice for a living, vs. the 49ers' two inside linebackers, Patrick Willis and NaVorro Bowman, whose jobs are to plug holes.
All three are first-team All-Pros.
All three are comfortable with collisions on the football field.
All three know full well the impact their jobs can make on the outcome Feb. 3 in New Orleans.
"Vonta, he's an animal," Willis says. "He plays the fullback as a true fullback. We had an opportunity to go against him last year. I'll be honest, you give credit where it's due and he's a hard-nosed fullback. There's no question in my mind that there are going to be times in this game where we'll have some one-on-ones, and we've got to come through. In this kind of game, at this kind of magnitude, it's all or nothing. We'll see."
When they played last year, on Thanksgiving Day, the 49ers lost, 16-6, but held their own against Leach and Rice, who finished with 59 yards on 21 carries.
The 49ers would probably settle for similar numbers in the Super Bowl. To do so, however, will require a lot more confrontations with Leach.
"He got the best of us at times last year," says 49ers Pro Bowl safety Donte Whitmer. "And we got the best of him at times. Their running game goes through him and Ray Rice. Rice is really the heart and soul of their offense, and if he gets going, you're going to have trouble on defense.
"We have to take their running game away. To do that, we have to be extremely physical with Leach and know where he is. Our linebackers, safeties and outside 'backers are going to have to make sure we're physical."
Bowman would expect nothing less in this matchup between intensely competitive brothers - coaches Jim and John Harbaugh - who have built their teams around physical running attacks and punishing defenses.
"Leach is good, definitely good," Bowman says. "(Jim) Harbaugh likes us to play physical, and I think they're a physical team, too. I think it's a great matchup. We'll see who the better man is."
If it ends up being the 49ers, Fangio might be in a position to expand on the topic of the current 49ers' linebacking corps vs. the Dome Patrol, the great linebacking unit of the New Orleans Saints in the late 1980s and early 1990s.
Like the 49ers, they played a 3-4 defense. The inside 'backers were Sam Mills and Vaughan Johnson. On the outside were Rickey Jackson and Pat Swilling.
They combined for 20 Pro Bowl selections.
Their young position coach was Fangio.
Fangio is now the coordinator of a defense with three linebackers who made first-team All-Pro this year - outside 'backer Aldon Smith, along with Willis and Bowman - and a fourth, outside 'backer Ahmad Brooks, who made second-team All-Pro.
So which unit is better?
"I have ducked that question for two years," Fangio says. "But if these guys stay humble and hungry, I will have a positive answer to that at some point."
Willis says he doesn't know anything about the Dome Patrol.
"I was in first grade back then," he says. "But I know we have one thing in common, and that's a good defensive coach leading us. We're fortunate to have coach Vic, and there would be nothing more gratifying than going out there on Super Bowl Sunday and all ending up champions."
It's not likely to be a collision-free route.
David Leon Moore, USA TODAY Sports