Chang W. Lee/The New York Times  The 49ersâ Mike Iupati at media day. He was one of two offensive linemen drafted by the team in the first round in 2010.  NEW ORLEANS — The San Francisco 49ers had an N.F.L.-high nine players selected to the Pro Bowl this season. At this week’s media day, eight of them sat on podiums in front of television cameras and masses of reporters. The ninth, Mike Iupati, the starting left guard, roamed through the crowd with far less fanfare.  It would have been easy to mistake Iupati, wearing his jersey and no pads, for a fan if he were not 6 feet 5 inches tall and more than 330 pounds. His size, along with a Mohawk-style haircut and arms covered in tattoos, make him an intimidating presence, right up until he speaks.  Iupati is a 25-year-old run-blocking specialist from American Samoa described by teammates as gigantic, fearsome and a monster, but he speaks softly, even taking the time to politely correct a reporter who mispronounced his surname. (It is you-PAH-tee, not eye-ooo-PAH-tee).  “Mike is just goofy,” said Joe Staley, the team’s Pro Bowl left tackle. “He loves to have fun. He’s like a big kid, the biggest kid you’ll ever see.”  But that fun and pleasant demeanor goes away when Iupati becomes a bulldozer clearing paths for a running game that has helped the 49ers reach the Super Bowl.  Having averaged 155.7 yards a game on the ground during the regular season, placing them fourth in the N.F.L., the 49ers have also excelled in the playoffs, with Colin Kaepernick setting a record for rushing yards in a game by a quarterback in the divisional round against Green Bay and Frank Gore chewing up time and running for 90 yards and 2 touchdowns in the N.F.C. championship game against Atlanta.  One of the biggest reasons for the success has been the team’s commitment to the interior line, an oft-overlooked component in a league that celebrates the left tackle.  For all of the talk of the read-option offense, the team’s versatile tight ends and Kaepernick’s strong arm, the 49ers have never wavered from their commitment to run.  “We like to play smash-mouth football,” said Tom Rathman, the team’s running backs coach and a noted 49ers fullback in his playing days. “Our philosophy is physical and talented. You want to move guys out of the hole to create lanes for the running backs, and I think that’s what our offensive line has done this year.”  LaMichael James, the team’s change-of-pace running back, thinks Iupati’s combination of size and speed is a key.  “When I’m running behind him, they really can’t see me too well,” said James, who is listed, perhaps generously, at 5-foot-9. “So I try to stay behind him. I just pick a spot and go.”  Gore praised Iupati’s ability to anticipate where the running backs may be going, but Iupati played that down, saying his strength was in blocking indiscriminately and letting those running behind him, including Kaepernick, handle the rest.  “Whatever color I see, I hit, and he knows that,” Iupati said of Gore. “He knows the reads, so he’s the one doing the job. I’m just there to block.”  They have played together for three seasons, and the comfort level between Gore and Iupati is apparent. During the regular season, Gore rushed behind the center and left guard 61.2 percent of the time, averaging nearly 5 yards a carry on those runs.  Gore’s runs behind right guard averaged just 3.7 yards, but Coach Jim Harbaugh brushed aside the suggestion that the team might have a preference.  “We feel pretty good running to either side,” Harbaugh said. “I think that may be more of a coincidence than a strategy.”  Still, Harbaugh praised Iupati as one of the best guards in the game, calling his line one of his “offensive weapons” against Baltimore.  “There’s no statistical agenda with those guys,” Harbaugh said. “They’re about playing the game, playing it tough, playing it strong, playing for a win and playing for a level of respect. That’s what drives our football team.”
Mike Iupati, a Pro Bowl guard, is a big reason the 49ersâ ground game has excelled this season.