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The vultures were circling above Colin Kaepernick.

The San Francisco 49ers were 6-4, coming off two straight losses in which the third-year quarterback played poorly. Niners fans and members of the media were starting to wonder if he was a liability.

Four weeks later, the narrative has changed dramatically.

Kaepernick is playing his best football of the season, and he is one of the biggest reasons why the 49ers could make a deep playoff run.

In his past four games, Kap has completed 61.8 percent of his passes for 888 yards, seven touchdowns and one interception. He is averaging 8.1 yards per attempt. And the 49ers are 4-0.

His most impressive half during that span came on Sunday.

In the first half against the Tampa Bay Buccaneers, who entered the game winners of four out of five, Kaepernick tossed two touchdown passes and rushed for 32 yards. He extended plays with his legs, which led directly to his TD pass to Michael Crabtree in the first quarter.

And just when the Bucs were devoting more defenders to stop him from scrambling, he beat them deep with the best pass of his career, a 52-yard touchdown strike to Vernon Davis.

By halftime, the 49ers had 17 points against a defense that had allowed an average of nine points in its previous six first halves.

Though Kap didn't play as well in the second half, the 49ers closed out the 33-14 win over the Bucs with great defense and special teams.

Which begs the question: How much do the Niners need from Kaepernick to make a deep playoff run?

Here's a look at Kaepernick's stats in his past four games compared with the past five Super Bowl-winning quarterbacks in their playoff runs:

Super Bowl-Winning QB Stats vs. Kap's Recent Form Player YPG TDs INTs YPA Joe Flacco (2012) 285 11 0 9.1 Eli Manning (2011) 305 9 1 7.5 Aaron Rodgers (2010) 274 9 2 8.3 Drew Brees (2009) 244 8 0 7.2 B. Roethlisberger ('08) 231 3 1 7.8 Kap (last 4 games) 222 7 1 8.1 B/R

Kap's number are right in the mix with these playoff heroes, though two caveats should be made about this before we go any further.

First, the 49ers haven't played playoff-caliber defenses in every one of their past four games. Second, the Niners defense is as good as—if not better than—any of the defenses of these Super Bowl winners.

So, Kaepernick will have to perform against some better defenses to keep up these numbers. But he also doesn't need to improve his numbers much—if at all—for the 49ers to have a great shot at winning it all.

Remember, the 49ers are 10-0 when he averages at least six yards per attempt. It ain't rocket science; when Kap plays relatively well, the 49ers win.

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With two weeks left in the regular season, Kaepernick and the 49ers are hitting their stride. Kap used his legs more effectively than he had all season against Tampa Bay. He escaped pressure and, at times, got past the pass rush and turned what looked like a helpless play into a positive gain.

He looked a lot like he did in the playoffs last year.

The entire offense has been running on all cylinders, averaging 25.5 points per game in the past four games. Not so coincidentally, Michael Crabtree's return three weeks ago has coincided with Kap's resurgence.

Defenses simply can't defend everything. The Bucs gave up two passing touchdowns and 187 rushing yards. The Seahawks allowed 110 rushing yards to Frank Gore and 163 rushing yards total. The Rams allowed Kap to throw for 275 passing yards. The Redskins allowed two touchdowns to Anquan Boldin.

Pick your poison.

Looking ahead, the 49ers are a win or Cardinals loss away from clinching a playoff berth. Assuming the Niners do secure the No. 5 or No. 6 seed in the NFC playoffs, they will likely need to win three road games to advance to the Super Bowl.

This is when Kap's resolve will be tested most.

If the 49ers win on Wild Card Weekend, they'll play the Panthers, Saints or Seahawks on the road—the three NFC teams San Francisco has lost to. CenturyLink Field, in particular, has been a house of horrors for the Niners signal-caller.

There's no way of knowing how he'll respond to the pressure. But if he can play like he has over the past four games, those vultures will surely be circling over the other NFC playoff teams.

Joseph Akeley is a San Francisco 49ers featured columnist. Follow him on Twitter.