49ers' Jim Harbaugh will soon know if gamble will pay off

Gambling isn't allowed in the NFL, but San Francisco 49ers coach Jim Harbaugh made a wager this season that would leave even the highest of high rollers weak in the knees.

He replaced hot-handed quarterback Alex Smith with Colin Kaepernick, a promising but largely untested second-year player.

That turned out to be a major roll of the dice - maybe the biggest in the league this season - and whether it was a wise move is still up for debate. The determining factor will be how well Kaepernick plays in the postseason, which for the 49ers begin Saturday night at home against Green Bay.

"Jim went all in, that's his nature," said ESPN's Steve Young, who in the early 1990s took over as quarterback of the 49ers from Joe Montana. "So when Colin played well in Chicago [in a 32-7 victory over the Bears on Nov. 19], Jim's reaction was, 'I've been looking for this.' . . . I don't think he looked back."

Smith led the 49ers to the doorstep of the Super Bowl last season, directing a home victory over New Orleans in the divisional round before losing in overtime to the visiting New York Giants in the NFC championship game.

On Saturday, the 49ers and Packers will meet for the sixth time in the postseason. Facing the Packers is especially meaningful for Kaepernick, who was born in Milwaukee and lived in Fond du Lac, Wis., before moving to California at 4. He was a Packers fan as a kid and a Brett Favre fan in particular.

Kaepernick, a 49ers second-round pick in 2011, got the starting nod as a fill-in for Smith, who had suffered a concussion against St. Louis. In the eight quarters that preceded that injury, Smith completed 32 of 35 passes for 385 yards with five touchdowns, an interception, and a passer rating of 140.2.

And with Smith at quarterback on this season's kickoff weekend, the 49ers beat the Packers, 30-22, at Lambeau Field.

But based on a feeling he had, Harbaugh stuck with Kaepernick, who's more mobile and has a greater potential for explosive plays.

"It was not a predetermined move," Harbaugh said earlier this week, adding: "It's pretty well-documented how we feel about both guys, that one's our left arm, one's our right arm. And both are very good quarterbacks."

Kaepernick has put up impressive numbers in his seven starts. He has completed 136 of 218 passes (62.4 percent) for 1,814 yards with 10 touchdowns and three interceptions. He has run for 415 yards and five touchdowns.