BALTIMORE (AP) — The Baltimore Ravens and San Francisco 49ers have thrived this season because they are physical, relentless and combative.
Just like their coaches.
The no-holds barred sibling rivalry between John and Jim Harbaugh moves to the national stage on Thanksgiving night, when they make NFL history by becoming the first brothers to compete on opposite sidelines as head coaches.
John Harbaugh is seeking to take the Ravens (7-3) to the playoffs for the fourth time in as many years at the helm. Jim Harbaugh has turned the 49ers (9-1) into Super Bowl contenders in his rookie year as an NFL coach by instilling his unyielding work ethic into a workmanlike offense and the league's stingiest defense (14.5 points per game).
The brothers received much of their football knowledge from their father, Jack, a longtime college coach. Their competitive spirit was honed during endless duels in almost every game imaginable — including a few they invented just so they could butt heads for boasting purposes.
"We would play tennis-ball basketball on a coat hanger rim," big brother John recalled. "We were throwing balls between tree branches, I guess, throwing snowballs against trees. It was whatever we could think of."
Sometimes, things got a bit out of hand.
"We have never had a fight as adults, maybe since we were 25 or something," John said. "But we had some knock-down drag-outs when we were younger. I can remember my mom screaming, wailing and crying, 'You're brothers! You are not supposed to act like this!' There are probably a lot of mothers out there that can relate to that."
John, 49, and Jim, 47, aren't the only pair of brothers who have dueled while growing up. They are, however, poised to become the only ones to take that competition into an NFL game as head coaches.
"It goes back to how hard both of them worked to get to where they're at today," said Joani Crean, their younger sister. "Nobody said, 'Oh, you're Jack Harbaugh's son, why don't you come do this job?' They both started out in their professions at the bottom rung, so to speak. They both worked their way up."
Their players know how important this game is to each brother.
"They're both competitive. We're competitive as a team," 49ers running back Frank Gore said. "Baltimore has a great team — they've been playing great ball for a while. Now we're doing our thing, so it should be a great game."
Ravens linebacker Terrell Suggs said, "We really want to win it bad for (John). We've (heard) they were going to kind of get after each other like they did when they were little. It's going to be fun to be a part of a sibling rivalry."
The last time John and Jim Harbaugh competed against each other in a sporting event was during an American Legion baseball game when both were teenagers. John was part of the an elite team and Jim wasn't, so little brother created a team of his own. Jim can remember virtually all of his teammates and the final score: Jim lost 1-0.
John's recollection of the game is not quite as precise, or so it would seem.
"We won. That's what I remember about it," he said. "I think I had the game-winning home run, too, if I remember correctly. At least as far as everyone here knows, right?"
The stakes will be much higher on Thanksgiving night, although to the Harbaugh brothers, it's just another chapter in a competition that will almost certainly continue for the rest of their lives.
"I'm really looking forward to it, and I think Jim is, too," John said. "Yeah, it's going to be very competitive, it's going to be very emotional. We're going to have a lot of family in town. It's one of those things in life where you don't get these moments back, you don't get these chances to live back. And this is a chance to live. Not just for Jim and I, but for the family, even the players and fans. If nothing else, it's something to remember. It's an event. It's cool."
The Harbaughs' parents will be at the stadium early, but will watch the game at John's house to "allow the stage to be John and Jim's. I want to rephrase that. Let the stage be the 49ers and the Ravens. I stand corrected," Jack Harbaugh said.
Some have dubbed this the Harbaugh Bowl, but it's also a very important game for both teams. The 49ers have won eight straight and are chasing unbeaten Green Bay for the top seed in the NFC. San Francisco can clinch the NFC West with a win and a Seattle loss on Sunday against Washington.
The Ravens are locked in a first-place tie with the Pittsburgh Steelers, one game ahead of surprising Cincinnati.
Jim Harbaugh loves the idea of squaring off against John again, although he'd have preferred a more neutral scenario.
"It's the first time in history that two brothers have coached against each other," he said. "This will be the first time since they went to a 16-game schedule that a team has traveled three time zones to play a Thursday game."
Asked how he will feel staring across the field at his brother, John said, "I'll be filled with so much pride and joy. And then probably some anger and other things once we start playing. But really, it's special."
AP Sports Writer Janie McCauley in Santa Clara, Calif. contributed to this report.