In Jim Harbaugh’s first year as head coach, the 49ers offense was first and foremost about establishing a running game.

Though Harbaugh was a former college and NFL quarterback, he believed his team had its best chance of winning by having Alex Smith hand off to the likes of Frank Gore and Kendall Hunter.

In 2011, the 49ers ranked third in the NFL in rushing attempts (498), eighth in rushing yards (2,044) and eighth in rushing yards per game (127.8) en route to building a 13-3 record and an NFC West title.

By contrast, San Francisco ranked 31st in the league – ahead of only Tim Tebow-led Denver – with 451 total passes attempted in 2011.

So, obviously, an offseason focus of the Niners and general manager Trent Baalke was to beef up the passing game to allow the 49ers more quick-strike options in 2012.

However, don’t expect the Niners to go away from the run this season.

In fact, with the addition of free-agent running back Brandon Jacobs from the Giants and the drafting of rookie speed back LaMichael James of Oregon, some believe the 49ers now have the best – or among the best – group of running backs in the NFL.

Gore’s talent and experience, Jacobs’ size and power, James’ potential and the improvement of Hunter and Anthony Dixon give the Niners depth and the ability to change up on defenses. The quintet also has the ability to offer receiving options out of the backfield. Gore, for instance, has five seasons with 40 or more receptions.

Speaking recently on a Pro Football Weekly panel, analyst Nolan Nawrocki says he believes the 49ers rank No. 1 in the league in having “the whole package” as the best corps of running backs.

“In terms of sheer talent I’ve got to go with the San Francisco 49ers,” he said. “What Frank Gore does on a down-to-down basis, he can run, he can catch, he’s outstanding inside the tackles and he’s got great vision.

“And you look at the complements they have, you’ve got Brandon Jacobs and the power he brings, and Anthony Dixon, if he makes that roster, he’s got a lot of talent as well. And even LaMichael James and Kendall Hunter, you’ve got two speed backs there that can really create big plays. So I think all around they’re as good as it gets.”

The Pro Football Weekly panel of three was split on which team has the best running back corps. Other teams in the mix are the Carolina Panthers (Jonathan Stewart, DeAngelo Williams form “Double Trouble,” plus have added Mike Tolbert) and New Orleans Saints (Darren Sproles, Mark Ingram, Pierre Thomas), with the Chicago Bears (Matt Forte, Michael Bush) and Houston Texans (Arian Foster and Ben Tate) right behind.

The Texans might have the best 1-2 punch, but for depth and variety the 49ers are hard to top.

How Harbaugh will work newcomers Jacobs and James into the mix will be interesting to see. Also, how many backs will the 49ers carry? Harbaugh has said he plans to carry as many as five running backs. But in addition to the top five, San Francisco signed versatile back Rock Cartwright from the Raiders (a special teams standout). Plus, second-year fullback Bruce Miller, one of the 2011 class of outstanding rookies, will help block for all of them.

One thing that hasn’t been evident yet is James’ role in this group. Until he shows what he can do in training camp and exhibition games against NFL defenders, observers will be left to only imagine.

But Harbaugh – who saw Oregon’s James while he coached Stanford – knows what James brings to the 49ers isn’t theoretical. It’s an explosiveness that’s very real.

“I’ve seen him play up close, seen all the things he can do,” Harbaugh told Cam Inman of the Bay Area News Group after James was drafted. “(We) lost games to his team by a large degree (because) of his efforts.”

Added GM Baalke of James: “He’s a playmaker.”