SANTA CLARA, Calif. — Shaun Hill's promotion didn't change him. He still plans to spend the San Francisco 49ers' bye weekend back home in Missouri, fishing and golfing and wearing a fat suit.

The quarterback can keep his Halloween plans with his girlfriend — they're going to dress up as two contestants on NBC's "The Biggest Loser" — and still have time to prepare for his third career NFL start Nov. 10 at Arizona. Not much bothers the laid-back veteran who suited up for his first five NFL seasons without taking a meaningful snap before leading the 49ers to two late-season victories last December.

After losing a training camp quarterbacks competition that many observers felt was handed to J.T. O'Sullivan, Hill is back behind center with a chance to run the offense that turned Kurt Warner and Marc Bulger into stars.

"I feel like I'm a lot further along than I was in training camp," Hill said. "Being able to sit back and watch J.T. in the offense helped as well, to kind of see some of those things in action that coach (Mike) Martz was talking about in training camp. These (last) eight weeks, I've continued to learn the offense, and I feel far more advanced in it now than I was back in August."

O'Sullivan was benched Monday by new coach Mike Singletary, who didn't share his offensive coordinator's tolerance for O'Sullivan's 11 interceptions and six lost fumbles. Together, that's more turnovers than any entire NFL team except the 49ers (2-6), who lost five straight games heading into their bye.

Hill played the second half of San Francisco's 34-13 loss to Seattle last weekend, showing off his usual calm in the pocket. He went 15-of-23 for 173 yards with one touchdown and no interceptions, leading two lengthy drives that looked good to fans who had grown tired of O'Sullivan's inconsistency.

Hill deflected any praise for the 49ers' improvements in the second half, saying the Seahawks' passive defense was the primary cause. But many observers, including Singletary, are quick to praise Hill's game management.

"I really don't know what all that means," Hill said. "I go out and I play each play the way I see it, and the way I've been taught. I guess if you can say at the end of the game that he managed the game well, I guess that's a compliment, most of the time, anyway."

Singletary cited O'Sullivan's turnovers as the main reason for the seven-year veteran's benching from his first NFL starting job. O'Sullivan fumbled on San Francisco's first two possessions against Seattle, and he was pulled after throwing an interception that was returned 75 yards for a touchdown.

O'Sullivan has looked sharp at times in San Francisco. But he also has fumbled 11 times — losing six — and been sacked 32 times under the constant pressure that seems almost inevitable in the recent incarnations of Martz's offense in Detroit and San Francisco.

"With Shaun Hill, it gives us confidence," Singletary said. "We're going to keep this thing together, and we're going to cut down on the mistakes, the turnovers, what have you, and let's give ourselves a chance to win."

Martz hasn't commented publicly about the quarterback change, but he had praised O'Sullivan in recent weeks for his improved maturity and pocket awareness — even if it didn't show up in his ballooning sacks total. After three months in Martz's system, Hill seems confident in his ability to execute it, whether or not Martz agrees.

"The structure is definitely going to be the same," Hill said. "Everything is going to be the same, but if you put two guys together, and they have the same training, if you send the two guys out there, it's still going to be two completely different games."