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Marcio Jose Sanchez, AP
San Francisco 49ers quarterback Colin Kaepernick, left, talks with Seattle Seahawks quarterback Russell Wilson (3) after an NFL football game, Sunday, Dec. 8, 2013, in San Francisco. The 49ers beat the Seahawks 19-17. (AP Photo/Marcio Jose Sanchez)

Only four teams remain in the NFL playoffs, and the storylines are juicy. The Seattle Seahawks host the San Francisco 49ers and the Denver Broncos host the New England Patriots on Sunday.

Arguably the biggest rivalry in the NFL exists on the West Coast between the Seahawks and the 49ers. The two teams just plain hate each other. They have split the last four matchups against each other, each winning at home over the last two seasons. Now, the heated rivals meet in the biggest game of the year so far. And no one expects either side to be nice.

The Seahawks were worried about fan altercations in their matchup in September, so they had undercover cops dress up as 49er fans, according to USA Today. Fans that were caught breaking the code of conduct were kicked out of the stadium and couldn’t return until they completed an online behavior course.

For this weekend's game, the Seahawks have gone far enough to limit 49er fans from purchasing tickets to the game on Sunday, according to Yahoo! Sports. They won’t sell tickets to credit cards with a California zip code. It won’t be impossible for 49ers fans to obtain tickets, but it will make it more difficult.

Sportsgrid.com reported that a group of 49er fans funded a billboard being placed in the Seattle area, mocking the Seahawks for their lack of Super Bowl wins. The 49ers have won five Super Bowls in their storied history.

Then there is the battle of the quarterbacks. Two of the youngest, most promising quarterbacks in the NFL — San Francisco's Colin Kaepernick and Seattle's Russell Wilson — have led their teams to the playoffs the past two seasons. Both became starters last season, and both were drafted to the MLB at one point.

But their public images couldn’t be more different. Seahawks fans compiled a list of Wilson’s and Kaepernick’s Instagram photos. The images went viral and boosted Wilson’s image as a charitable family man while making Kaepernick look like a self-centered thug.

Another huge aspect of the rivalry is the deep history between the coaches, John Harbaugh and Pete Carroll. Their rivalry dates back to the Pac-10 days when Harbaugh coached Stanford and Carroll coached USC.

Now in the NFL, their rivalry has deepened. There has been an endless amount of smack talk, but the most famous came back in 2012 when Harbaugh accused Seahawk Bruce Irvin of cheating when Irvin was suspended for a failed PED test. Seahawk teammate Brandon Browner jumped to Irvin’s defense.

"He's a coach. He's never gonna be out there lined up against me,” Browner told KJR-AM, as reported by the Seattle Post-Intelligencer. “I wish he would; I'd put my hands around his neck. At the end of the day, I'm about winning football games."

No doubt tempers will fly when the hated rivals face off on Sunday.

The other Sunday matchup features two of the greatest quarterbacks to ever play the game when Denver's Peyton Manning and New England's Tom Brady square off with their respective teams.

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This is Manning and Brady’s 15th matchup against one another. Brady holds a 10-4 record against Manning, including a 2-1 edge in the playoffs. In the two seasons Brady beat Manning in the playoffs, Brady and the Patriots went on to win the Super Bowl. Manning, likewise, went on to win the Super Bowl after his lone playoff victory against Brady.

Manning was drafted first overall in the 1998 draft, and Brady was selected with the 199th overall pick in the 2000 draft. Despite the differing draft positions, Brady has won three Super Bowls compared to only one for Manning.

Not surprisingly, Manning and Brady are first and second in overall wins for active NFL quarterbacks. In career winning percentage among active starting quarterbacks, Brady is first and Manning fourth. Who are numbers two and three? Kaepernick and Wilson.

Follow Trent on Twitter @TheRealTrento.