SANTA CLARA -- Defense is expected to win Sunday's NFC Championship game, meaning either the 49ers' Colin Kaepernick or the Seahawks' Russell Wilson will be the losing quarterback, quite possibly because of the turnover factor.

Kaepernick knows such peril in Seattle, having accounted for three interceptions and a lost fumble in his last visit -- a 29-3 loss on Sept. 15.

"We do have to protect the football," Kaepernick said Wednesday. "That's something that we haven't done very well up there."

But that's something he's done quite well in the 49ers' eight-game win streak (two interceptions in 223 passes). Kaepernick threw eight interceptions all regular season, one less than Wilson's total.

"The Seattle defense is looking to get the ball at all times, create turnovers in any situation, generate them on all downs," 49ers coach Jim Harbaugh said.

The Seahawks rang up an NFL-high 39 takeaways in the regular season, including 11 interceptions in their three games after losing 19-17 to the 49ers on Dec. 8.

Kaepernick had a pass intercepted in that Week 14 win, a deep pass to Michael Crabtree that Byron Maxwell intercepted at the 3-yard line. The Seahawks failed to convert that turnover into points, however.

"The only time I felt not in control was the last time at Candlestick," Seahawks safety Earl Thomas said. "I was looking at myself like, 'You're supposed to be a leader and you look all off. You're not on your tempo. Your rhythm is all off.' "

Thomas produced just one takeaway the past 10 games, but he's the leader of a heralded secondary, which the 49ers may be forced to test if they can't get their running attack on track with Frank Gore & Co.

"They have a good defense, so there's times that they make plays," Kaepernick said. "The more we can eliminate that and make plays on our side of the ball, the better off we will be."

Harbaugh's instructions to Kaepernick and others: "Remind them to protect the ball, daily and hourly."

Seattle didn't intercept any of Drew Brees' 43 passes in last Saturday's 23-15 divisional-round win over the Saints. But the Seahawks did parlay a fumble by running back Mark Ingram into a touchdown, when Marshawn Lynch scored two snaps later for a 13-0 lead early in the second quarter.

Wilson served as an, ahem, game-manager in that win, completing 9 of 18 passes for a mere 103 yards. Unapologetically, he mostly handed off to Lynch (28 carries, 140 yards, two touchdowns).

"Why wouldn't you keep handing it to him?" Wilson said. "But we have a great passing game. We can do things on time, on the money. We're explosive in the passing game, have been all year."

Wilson has cooled, however, since starting 11-1 this season and posting a 90-plus passer rating in nine of those games. Only one of his past five games has featured a plus-90 passer rating, with no more than one touchdown pass in any of those games and three total interceptions.

Both Wilson and Kaepernick had ugly passing lines before halftime of their last Seattle encounter, on Sept. 15: Wilson was 2 of 10 for 48 yards, Kaepernick 6 of 14 for 46 yards, and each had an interception with no touchdown passes. Neither finished with more than 150 passing yards.

When it comes to ball security, Wilson and Kaepernick are two of the NFL's most elusive quarterbacks, and that ball could pop loose on one of their scrambles. Wilson has five lost fumbles this season, Kaepernick four.

How often do they run? Perhaps not as much as most think: Kaepernick had 92 carries for 524 yards and four touchdowns in the regular season, and Wilson had 96 carries for 539 yards and one touchdown.

That's 1,063 rushing yards combined, a stark contrast to the minus-13 yards rushing by their counterparts in the AFC Championship game: the Broncos' Peyton Manning (32 carries, minus-31 yards) and the Patriots' Tom Brady (32 carries, 18 yards).

Awaiting Kaepernick at Seattle's amphitheater is the ever-loud 12th-Man crowd. It's quite the X-factor, or XII-factor, if you will.

"We only have 11 on the field, just like them," Kaepernick said.

His and Wilson's ultimate job: Make sure the ball stays in the hands of the 11 players on their respective side.

For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers. Follow him on Twitter at twitter.com/CamInman.

SUNDAY'S CHAMPIONSHIP GAMES
AFC: New England at Denver, noon CBS
NFC: 49ers at Seattle, 3:30 p.m. FOX

INSIDE
What Harbaugh would give up for a chance to suit up Sunday. PAGE 4

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