Alex Smith’s first NFL start was a putrid affair. Looking jittery and overmatched, the 49ers’ rookie threw four interceptions, was sacked five times and had an 8.5 passer rating.

When it was over, Colts cornerback Nick Harper said it was easy.
“He stared down his first read,” he said. “All we did was take it away.”
That’s how they got four interceptions?
“The goal was five,” Harper replied.
On Sunday in Indianapolis, Smith gets a chance to show how much he’s grown up. He’s the starter again, just in time for a rematch with the team that tormented him in a 28-3 defeat on Oct. 9, 2005.
Asked on Wednesday to look back at his first game against the Colts, Smith smiled.
“A lot has changed since then,” he said.
The 49ers sure hope so. This is the toughest game on their schedule. The Colts are 6-0 and winning games by an average score of 30-13.
Indianapolis boasts the NFL’s sixth-ranked passing defense (236.0 allowed per game) and a Hall of Fame quarterback who makes it almost impossible for mortals to keep pace. Peyton Manning has 32 touchdown passes against seven interceptions during the Colts’ 15-game regular-season winning streak.
Indianapolis also has defensive ends in Robert Mathis and Dwight Freeney, who grow increasingly dangerous each time the Colts pad their lead. Indianapolis has outsacked teams 418-216 (an NFL-best +202) since Manning arrived in 1998.
Welcome back, Alex!
“They are fast and they get after the quarterback,” Smith said when asked about the Colts’ defense. “That team is set up very well. They are good at playing with the lead. I think they force teams into playing one-dimensional because (opponents) are playing from behind, then you have to throw the ball.
“That is what they want as far as the defense goes: They want you to sit back in the pocket and throw the ball.”
The 49ers are betting that Smith is much better prepared for this challenge than he was when he took over for Tim Rattay early in the 2005 season. Mike Singletary made the quarterback switch this week, naming Smith the starter over Shaun Hill.
It was done partly because Smith’s confidence is on the upswing again.
“Alex is a totally different guy today than he was even six months ago. He’s just a totally different guy,” the 49ers coach said. “I think his mindset is clear. The thing that spoke volumes to me about him was in the off-season he had a chance to move on and go to another team and make more money.
“But he decided to stay because he felt that he wanted to be a part of what was here. He wanted to finish what he started.”
Of course, Smith didn’t get the promotion simply because of his clear mind. Demeanor is Hill’s forte. But the 49ers quickly discovered that guile could only get them so far down field and concluded that Smith’s stronger arm could stop defenses from putting eight or nine men in the box.
Smith’s presence isn’t just about airing it out: The mere threat of a passing game could open more lanes for the 49ers’ 22nd-ranked running game and take some pressure off a struggling offensive line.
It worked, at least for a half, in Houston. Smith came off the bench last week to become the first 49ers quarterback to throw three touchdowns in a half since Jeff Garcia (four TDs) did it on Dec. 7, 2003.
Much of Smith’s success came against a Texans defense playing loosely because of a 21-0 halftime lead. Now, the quarterback must do it from the opening kickoff against a team with a .793 home winning percentage (46-12) since 2002.
Singletary said he has done his best to keep Smith prepared, both physically and mentally. Even when he selected Hill to start the season as the starter, the coach told Smith, “I don’t want you to go lock yourself in the barn.”
Does Smith recall that conversation?
“I never got the barn quote,” he said with a laugh, “but this is the NFL. If you’re a backup quarterback and you think you’re not going to play, you’re in a dreamland.
“How many QBs go through a season and take all the snaps and can handle that? It’s not a lot. I think you have to have the mindset. You have to have the expectations to play. The question is, when does it come?”