As a rookie head coach, John Harbaugh once showed up for interview session after practice with a rather noticeable fresh welt under one eye. He liked to get right into some of the Ravens' drills, lining up at defensive back or on special teams. The drills weren't supposed to be full-contact, but it's football, and this particular day, something had gone awry and a wide receiver had smacked right into his coach.

He was 46 then, well past the age when a coach should be mixing it up with a prime-time NFL player. But he is a Harbaugh, and they do things their own way.

"He doesn't do it as much as he used to five years ago,'' linebacker Brendon Ayanbadejo said with a laugh, still mildly amazed that it happens at all, "but Coach Harbaugh will get out there and run down the field on kick coverage, and we'll have to try to block him. Sometimes, we'll have guys from the Navy or Marines visiting practice, and he'll get them out there with him. They're these young guys, in great shape, and they love it.''

It's important to establish here that the elder Harbaugh brother, the first son of the family that a TV network dubbed the "The First Family of Coaching,'' has his own mad methods and off-kilter competitiveness. John is not the vanilla alter ego of the Nutty Butty-Rocky Road-Flaming Baked Alaska who shares his DNA and coaches the 49ers.

It's just easy to cast the big brother that way, because Jim's eccentricities can fill a bottomless vat. A tape of him uttering  "jive-turkey gobblers'' should play on continuous loop in Canton. The quote belongs on sportswriters' headstones. Those of who wish to be cremated should reconsider for that reason alone.

Plus, there's the fact that Jim moved into a haunted house in San Francisco, quickly fortified the skeletons and rehabbed the joint to past splendor. John slid into a comfy spot, taking over a team that had gone 13-3 two seasons earlier and made the playoffs in four of the eight previous years.

But all ancillary drama aside, the Brothers Harbaugh have arrived at the same spot two years in a row. When their teams won last weekend in the divisional playoffs and advanced to their conference title games, a few wits suggested that franchises in search of a head coach contact their younger sister, Joani. 

Not long after the matchups were set, calls went into the Wisconsin home of the Parents Harbaugh – Jack and Jackie – asking where they'd be on Sunday, when their boys are in Atlanta and New England fighting for a spot in the Super Bowl. In their Mequon basement, watching on TV by themselves and sweating out every second, they said.

"They put their whole lives into raising three kids, and all they want is for their kids to be happy,'' Joani said from her home in Indiana. "And a lot of that, in this profession, comes from winning. So it is hard for them to watch.''

The parents had planned to stay there on Thanksgiving 2011, too, when the NFL gave the family the dubious gift of pitting Jim and John's teams against each other on a national holiday. Then they decided to go to Baltimore after all, but to retreat to John's suburban home after pregame photos. At the last minute, the Ravens found a stadium office where they could sit and watch, away from the cameras and reporters or even fans who could watch their reactions.

So they were there after the game to meet with their sons, the winner John and the loser Jim. They went to Jim's locker room first, Jack going inside, Jackie waiting in the hallway outside. She looked exhausted and smiled wanly as someone came over and squeezed her hand.

"I think they'll be happy for us," John had just said at his post-game news conference, "but they'll be way more disappointed for all the 49ers' players and coaches. I'm sure that's where they are right now, and that's where they should be."

The distress probably doesn't make sense to most people. Their sons have two of the 32 most coveted jobs in the world, and they're really good at them. A Super Bowl meeting should be an incomprehensible dream for a family whose parents spent the day after their wedding at an Ohio State-Michigan game, for the father who worked 43 years in the college ranks, for the sister who married into a parallel world after she met future Indiana basketball coach Tom Crean during Jack's time at Western Kentucky.       

And the Harbaughs do understand their great fortune. They know how to savor it.  Have you seen any of the footage of the 49ers doing that call and response chant after a win: "Who's got it better than us? Nobody.'' Well, that's a hard-rock cover of a folk song delivered by Jack and Jackie. All red-cheeked and merry, they demonstrated the chant once in the Candlestick parking lot after a 49ers win. They've been doing it forever, first when John, Jim and Joani were munchkins, and now for their grandchildren. The parents stretched out the "Nooooo-body'' and hit the consonants hard. If they don't know life is good, they fake it very, very well.

But they wouldn't be the only parents to feel deeply conflicted about watching their offspring square off in competition. Richard Williams made his anguish known when Venus and Serena met on a tennis court, and the sisters routinely described the experience as excruciating.

Archie Manning called Jack Harbaugh before the Thanksgiving showdown and shared thoughts on the two times he had to watch Peyton and Eli play against each other.

According to Jack Harbaugh, Manning said: 'The only advice I can give you is it will be over.''          

John is 50, Jim just 15 months younger. At this age, people with beloved siblings tend to know that they have something special, that many other apparently happy brothers and sisters grew into alienated adults. Maintaining these relationships requires humility, a certain pacifism and a marginalized need to be right. Success at the highest level of sports, in the moment of confrontation, demands the opposite.

Combining the two endeavors, even briefly, would be a contortionist's act. Watching your children try to pull it off? To paraphrase the famously OCD Adrian Monk, who just might be Jim Harbaugh's sweet and gentle twin, it would be mostly a blessing and a smidgen of a curse.

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One of the hard rules endorsed by the Harbaugh family is: no comparisons. They don't like to measure one player against another, or brother against brother.

"What it does is it ends up diminishing one side or the other,'' John said once, when asked what traits separated him and Jim. "So I never answer those.''

One of the officials in their Thanksgiving game offered the most candid answer about the two in an exchange captured on the NFL Network's "Sounds of the Game.'' The side judge had moved from the 49ers' sideline to the Ravens' after halftime, and John asked about his brother's reactions to first-half calls: "Was he hot over there?"

The judge replied: "You guys are a lot alike. That's all I've got to say."

When Jim joined the 49ers in 2011, he rearranged the locker room so that stalls alternated between defensive and offensive players, breaking up the cliques that formed when positions clustered together.

"I think it was good, because it kind of helps you not get into wanting to point fingers at the other side when things aren't going the way you want,'' defensive lineman Ricky Jean Francois said.

John had done the same thing when he arrived in Baltimore in 2008. It sounds gimmicky, but NFL locker rooms divided by position often do develop a Balkanized quality.

Jim handed out retro short-sleeved blue shirts with each player's first name on a patch, like an auto mechanic's uniform. John had done the same thing with the Ravens.

Both brothers use Muhammad Ali, their father's favorite athlete, as a motivational prop. Jim posted a photo in the 49ers' locker room. John sometimes spliced footage into game film. This fall, the real article, the champ himself, came to the Ravens' training facility for a visit. Jack Harbaugh was there that day, bouncing around like a man half his age, shadowboxing, according to Ayanbadejo.

Jack Harbaugh shows up periodically at both sons' camps; he reviews game film for them each week, and he has spoken to the each son's players.

The Harbaugh all share a love of military history, not uncommon among football coaches, and when HBO's "Real Sports" did a feature on the first family of football, the crew met them at Gettysburg. On a trip to Washington last season, the 49ers visited Arlington National Cemetery, and developed an attachment to the officer who led them around. Jim named a play in his honor.

The most critical difference is Jim's success as a player, at quarterback for Michigan and then as a first-round draft spending 15 years in the NFL. John played to less acclaim at Miami of Ohio, then turned to coaching immediately.

The disparity in their athletic careers jolted the elder son's academic and coaching ambitions. He has said as much more than once: "I felt like I had to catch up.''

Does that explain the difference in their styles? John's personality has an edge, just like most coaches', but his brother's is a razor.

The two of them each had had handshake malfunctions in the NFL. John's was merely testy, an awkward exchange with Steelers coach Mike Tomlin that became easily overlooked. Jim's was a sequel, the rarest kind. It surpassed the original -- the collegiate Pete Carroll turning "What's your deal?'' into a catch phrase after a two-point conversion. Jim Schwartz's sprint to confront Jim Harbaugh over a back slap that punctuated their handshake should, by all rights, end up as a definitively combative moment in the coach's career.

But he's just getting started in his career, and "jive-turkey gobblers'' has moved into contention. That episode, by the way, started after Yahoo!'s Mike Silver analyzed a 49ers' win over the Seahawks and wrote that the play-calling reflected the coach's lack of confidence in quarterback Alex Smith. Within weeks, Harbaugh had proved the gobbling more than half-right, allowing Colin Kaepernick to keep the job after Smith recovered from a concussion. Harbaugh liked Smith and cultivated him, but he hadn't completely committed to him.

A piece on John Harbaugh by Silver went in another direction, discussing an emotional confrontation between coach and players that John turned into a therapeutic event, accepting criticism and promising to communicate better.

Ayanbadejo, reached by phone, wouldn't discuss the story, but he vouched for his coach's open ears. "He'll listen to what we say and he'll ask us for our opinions instead of lecturing at us,'' he said. "It's different from anything I've seen in football.''

In San Francisco, the 49ers feel free to tease their coach and to talk to him like another player. When a YouTube video of quarterback Jim's long-ago appearance on the sitcom "Saved by the Bell'' surfaced a few months ago, the ribbing reached new heights. "We were all calling him 'Screech's cousin,'" Jean Francois said, "just hollering it at him when we were going out onto the field.''

The underlying point, though, is that the guy has star power, even if some of it derives from a corny old sitcom. Find Sean Payton or Mike Smith in such a clip.

The belief that Jim is completely useless to the media is somewhat overstated. He can be caustic and unpleasant, depending on his mood, and he does not share tidbits with favored reporters. He can also be plainly goofy, whether citing "Freddie P. Soft'' as the secret agent of overconfidence or going on a riff about the statue the team should build of Frank Gore. During a brief stint on Twitter, he randomly typed up stanzas from Gordon Lightfoot's "The Wreck of the Edmund Fitzgerald.''

Before the Thanksgiving showdown last season, he went on and on about how their teachers loved John and found themselves perplexed to discover the difficulties of dealing with his younger brother. Jim never seems more humble than when discussing his family, especially John. He says his big brother was his staunchest supporter, and remains his best friend.

"I'm half the coach he is,'' he has said several times.

That may not be true, but Jim sells it hard, and it calls to mind a moment after the Super Bowl last year, when Eli Manning stood on a riser during the trophy presentation. He had been asked about Peyton several times, looking uncomfortable when reporters said that his two championships surpassed his brother's one. Then he saw the eldest Manning brother, Cooper, whose football career had been derailed by injury, down on the field. Eli took a football and threw a spiral down to his big brother, who caught it. Amid all that pageantry, they had shared this intimate, fraternal moment.

If they're lucky, these football siblings can push each other upward. If they're really lucky, the game always pulls them closer together.