QUARTERBACKS

The assignment: Shaun Hill was supposed to manage an offense driven by a powerful running game. When that running game failed, Hill was replaced by Alex Smith, who coaches believe can better open up the offense in the absence of a strong ground game.

Progress report: Smith has shown flashes of being the quarterback everyone expected him to become. But Sunday's loss to Tennessee also showed that he is capable of lapsing into the mistake-prone quarterback who mostly has frustrated fans since 2005.

The grade: C+

RUNNING BACKS

The assignment: The 49ers thought they could use Frank Gore and the running game as the foundation for the rest of the offense.

Progress report: Defenses easily have outmatched the 49ers by stuffing eight defenders along the line of scrimmage. Gore missed nearly three games with an ankle injury, but he showed Sunday that he can be a top running back when he gets room to maneuver. Glen Coffee was excellent in the exhibition season but has been only so-so in the regular season.

The grade: B

WIDE RECEIVERS/TIGHT ENDS

The assignment: The 49ers wanted their receivers to be part of their ball-control philosophy and to complement the running game.

Progress report: The early-season starters, Josh Morgan and Isaac Bruce, didn't put pressure on defenses. Instead, Michael Crabtree and tight end Vernon Davis, who is having a Pro Bowl season, have been the biggest threats. Look for the 49ers to turn to a youth movement at wide receiver as the season progresses.

The grade: C

OFFENSIVE LINE

The assignment: The 49ers spent the bulk of the offseason implementing a running game designed to bowl over opponents and win games in the second half.

Progress report: The unit has not been close to the powerful force coach Mike Singletary and offensive coordinator Jimmy Raye imagined. Injuries have plagued the tackle position, while the guard play at the start of the season was terrible. The 49ers rank only 21st in rushing yards, and they have given up 26 sacks, the fourth-highest total in the league.

The grade: D

DEFENSIVE LINE

The assignment: The linemen in San Francisco's 3-4 scheme aren't supposed to be flashy. They are expected to hold their blocks and maintain their gaps so that the linebackers can make the plays.

Progress report: All of the team's starters, Isaac Sopoaga, Aubrayo Franklin and Justin Smith, have at times played very well this season. Offensive lines often double-team the relentless Smith while guards and centers have found Franklin to be a handful. Teams rarely have been able to rush up the middle against the 49ers.

The grade: B+

LINEBACKERS

The assignment: The linebackers are supposed to be the playmakers in the 49ers' scheme, both as far as making tackles and applying pressure to the quarterback.

Progress report: There may be no better tackler in the league than Patrick Willis, who chases down ballcarriers like a jungle cat. The 49ers have had few game-changing plays, and that reflects poorly on outside linebackers Parys Haralson and Manny Lawson. Haralson led the team in sacks last year, but he has only one this season, and it came in Week 1.

The grade: C+

DEFENSIVE BACKS

The assignment: The 49ers wanted two things from their defensive backs this season – no big offensive plays and more turnovers. The 49ers replaced Mark Roman with Dashon Goldson at free safety hoping the move would supply more interceptions.

Progress report: With the exception of Falcons wide receiver Roddy White's 90-yard touchdown in Week 5, the 49ers have kept explosive plays to a minimum. The unit has only four interceptions, but that's primarily a product of an anemic pass rush. One starting cornerback, Shawntae Spencer, has played well, but the future remains cloudy for high-priced Nate Clements.

The grade: B+

KICKING TEAMS

The assignment: Field position has been critical to the 49ers, who want to increase the chances that their opponents make a mistake by forcing them to march the length of the field.

Progress report: Punter Andy Lee has been one of the best in the league, as shown by his performance against the Titans. Kicker Joe Nedney has only 11 field-goal attempts on the season, but has made nine of them.

The grade: A-

RETURN TEAMS

The assignment: The 49ers seemed to favor safety over flash in the return game, but they parted ways with veteran return man Allen Rossum after several lackluster games. Since Rossum left, the 49ers have taken a committee approach, both on punt returns and kickoff returns.

Progress report: The 49ers have gotten little pop on kick returns while punt returns have been terrible. One return man, Arnaz Battle, flubbed a punt deep in his own territory in Houston, another, Clements, broke his shoulder on a return while a third, Brandon Jones, goes sideways and backward more than he goes forward.

The grade: F

COACHING

The assignment: Singletary wanted to build on the foundation laid by Mike Nolan by making the 49ers into a tough-minded and physical team in the finesse-heavy NFC West.

Progress report: Singletary has found that tough talk doesn't translate into tough play. He is on the verge of abandoning the power-running style that was supposed to anchor his offense. Still, Singletary hasn't lost faith, and more importantly, the faith of his players.

The grade: C+

Read Matthew Barrows' archives and blogs at www.sacbee.com/sf49ers.