SAN FRANCISCO -- Coach Jim Harbaugh saw what you saw. All the San Francisco 49ers did. They know what you're thinking about Colin Kaepernick declaring his case to unseat Alex Smith as the starting quarterback. Sounds like they're right there with you.

The only question now is when it's going to happen. Is Monday too soon?

"I usually tend to go with the guy who has the hot hand," Harbaugh said after watching Kaepernick sling the football all over Candlestick Park and through the Chicago Bears' defense during a 32-7 demolition job Monday night.

That would have to be Kaepernick with the hot hand, no?

"We really have two guys who have a pretty hot hand," Harbaugh said, "but we'll make that decision as we go forward."

Harbaugh has every reason to muddy the picture for the New Orleans Saints, the 49ers' Week 12 opponent. League rules prevent him from restoring Smith to the lineup until the quarterback passes concussion testing. But he could have paid tribute to the 19-5-1 starting record Smith has posted since Harbaugh arrived. He could have propped up Smith the way he has done so many times before. Instead, he basked in Kaepernick's glow.

Harbaugh would not say whether Smith would remain the starter if doctors cleared him in time to play against the Saints.

"We'll make that determination as we go," he said.

Harbaugh's unflinching public support for Smith over the past season-plus should not obscure another reality: Harbaugh and the 49ers traded up for Kaepernick in the second round of the 2011 draft because they thought he could do what he did Monday night, albeit probably not right away.

Kaepernick completed 16 of 23 passes (69.6 percent) for 243 yards and two touchdowns against what had arguably been the baddest defense in the land. He changed plays at the line of scrimmage. He made sophisticated downfield throws into secondary windows. He stared down blitzing linebacker Lance Briggs before firing a touchdown pass to Vernon Davis. He was the foundation of the 49ers' offense from the beginning of the game.

"Colin is the man," Davis said.

Late in the game, well after Kaepernick had staked the 49ers to an insurmountable lead, he threaded a pass to Davis against blanket coverage on third-and-12. The throw so impressed Davis that the Pro Bowl tight end put his hands together and bowed before his quarterback.

"I'm just so proud of him in that moment because the ball that he threw me, it was just one of those balls that you see Tom Brady throw," Davis said. "Second window, right on the money. Surprise. I didn't expect the ball to come because we ran that play quite a few times and the tight end usually don't get the ball on that play."

By this time, it was clear no one in the 49ers' locker room was going to discourage, or even temper, the idea that Kaepernick had announced his arrival Monday night. The Bears were impressed, too.

"His first start, to play like that on a national stage, normally it doesn't work like that," Bears coach Lovie Smith said.

Conventional wisdom says this was only one game. It says Smith has built up sufficient equity to withstand such a charge. It says an established starter shouldn't lose his job to injury (a rule Harbaugh said he doesn't observe). Then again, conventional wisdom said the 49ers would lean on their ground game to protect a young quarterback making his first start. Conventional wisdom said Kaepernick would struggle against an elite defense.

Conventional wisdom never said Kaepernick would finish his first start with a 133.1 NFL passer rating, or that he would post the highest single-game Total QBR score for a first start in the five-year history of the metric. Kaepernick checked in with a 97.5 out of 100. That beat the NFL debuts for Robert Griffin III (93.8), Matt Ryan (89.2), Aaron Rodgers (88.5) and -- cough, cough -- Tim Tebow (84.6)

The book on Kaepernick coming out of Nevada read a bit like the book on Tebow. Both had been prolific rushers. Both faced potentially problematic adjustments to pro offenses. Kaepernick had topped 10,000 yards passing and 4,000 yards rushing during his college career. He hadn't played many regular-season snaps as a conventional quarterback until taking over for Smith against St. Louis last week. He got better as that game progressed, but there were few indications he would play the way he did Monday night.

Tebow posted that 84.6 QBR for Denver against Oakland in 2010 on the strength of eight rushes for 78 yards and a touchdown. He completed 8 of 16 passes for 138 yards. He was a running back playing quarterback. He was limited.

Kaepernick played a different game against the Bears. He came out throwing and completed 12 of 15 passes for 184 yards and a score in the first half. He rushed only twice in the half and four times for 12 yards overall. He did the things analysts say NFL quarterbacks must do. Surprisingly, he changed plays at the line and made only one pre-snap mistake, by Harbaugh's count. That remains the one area that Smith should have an overwhelming advantage. Perhaps that advantage is less pronounced than anticipated. Perhaps conventional wisdom doesn't apply here.

When asked about the one thing that impressed him most, Harbaugh listed five things.

"Accuracy, the poise in the pocket, again you saw the running ability, playmaking ability, understanding of the game plan," Harbaugh said.

Davis, an afterthought in the passing game lately, said he felt as though the handcuffs had come off his wrists. Kyle Williams, whose 57-yard reception on third-and-7 set up the 49ers' first touchdown, marveled at Kaepernick's consistent accuracy.

"We all know the talent that he has and what he is capable of," Williams said, "but him just coming out there and just balling like that, making every throw, it's tough to say that you expected him to come in and make every single throw like he did."

Kaepernick, resigned to the bench while the 49ers won with Smith's generally efficient play, knew this might be his one chance to win the job this season. He played like it, too.

"Definitely, I wanted to come out and show what I'm capable of and show that I can be a starter," Kaepernick said. "That's what I've been trying to prove since I've been in the league."

OK, then. Let's ask the question. Which quarterback should the 49ers start against New Orleans? Conventional wisdom says it has to be Smith. And if the Saints had a vote, I suspect they would agree.