(10-26) 23:01 PDT -- It's folly to assess the quality of an NFL draft class less than halfway into a season.

Six games? Six years is probably a more appropriate length of time to wait before handing out final letter grades.

Still, Charley Casserly, a general manager for 16 years with the Redskins and Texans, says the 49ers should already be feeling good about the Class of '11, which has produced four rookies who have contributed significantly to their 5-1 start.

"The reality is that you should wait," said Casserly, a CBS Sports analyst. "But a lot of times you do have a feel. And the 49ers should be feeling good. You look at someone like Aldon Smith and say, 'Well, why isn't this guy going to be an excellent player in the league?' ... Right now, their draft class is off to a great start. They should be happy with it. They should be proud of it. (General manager) Trent Baalke's done a good job. There's no reason to believe these players won't continue to get better."

Indeed, based on the early returns, Baalke's second draft might top the Class of 2010, which has produced three starters in first-round offensive linemen Anthony Davis and Mike Iupati and linebacker NaVorro Bowman, a third-rounder who is off to a Pro Bowl caliber start to 2011 (team-high 9.7 tackles per game).

This season, Smith (5.5 sacks), the No. 7 overall pick, has offered first-round production. But the Niners have also received contributions from cornerback Chris Culliver (third round), running back Kendall Hunter (fourth round) and converted fullback Bruce Miller (seventh round).

Of course, it's quite possible this year's draft class won't look quite as good in a few years.

On the other hand, it could look even better.

Who knows, for example, what the 49ers might have in second-round quarterback Colin Kaepernick. Or interior linemen Daniel Kilgore (fifth round) and Mike Person (seventh round). Or special-teamer Colin Jones (sixth round) and cornerback Curtis Holcomb (seventh round), who is on injured reserve.

At this point, there are still plenty of questions surrounding the Class of '11. But the preliminary answers are encouraging.

Aldon Smith

Asked to compare 49ers rookie Aldon Smith to Houston linebacker Mario Williams, whom he selected No. 1 overall in the 2006 draft, former Texans general manager Charley Casserly mostly articulated their differences.

Williams, he said, is stronger. And Smith is probably more athletic.

But Casserly, now a CBS Sports analyst, did settle on a notable similarity.

"I think at the end of the day, the end result is that Mario went to the Pro Bowl and (Smith) should go to the Pro Bowl," Casserly said.

That's high praise considering Smith, 21, has yet to start an NFL game. But it's an indication of well how the No. 7 overall pick has performed in part-time duty in his first six contests.

Consider that with 5.5 sacks this season, Smith is on pace to tie the NFL rookie record (14.5) set by Tennessee's Jevon Kearse in 1999 (sacks became an official stat in 1982). In addition, Smith, at his current pace, would have the most sacks by a 49er since Chris Doleman had 15 in 1998 and would be the first to record a double-digit sack total since Andre Carter had 12.5 in 2002.

The 49ers had planned to convert Smith, a defensive end at Missouri, to outside linebacker in their 3-4 defense. But Smith, listed as a linebacker, has played almost exclusively at defensive end in San Francisco's nickel and dime packages.

There have been questions about Smith's ability to drop back into coverage as a linebacker and keep up with running backs and tight ends, but Casserly says those concerns are overblown.

Williams, who moved from defensive end to linebacker before suffering a season-ending pectoral injury Oct. 9, wasn't doing much backpedaling, Casserly noted.

And Smith, whenever he settles in at linebacker, will also be playing to his considerable strengths.

"I would think that Aldon Smith is going to spend almost all his time going forward and not a lot of time in coverage," Casserly said. "... You didn't draft this guy to go back and cover people. You drafted him to get to the quarterback."

Chris Culliver

After the 49ers used a third-round pick on South Carolina cornerback Chris Culliver this spring, former NFL scout Dave Razzano thought of safety Taylor Mays, San Francisco's second-round selection in 2010.

Like Mays, Culliver has excellent size (6-feet, 199 pounds) and speed (4.36 seconds in the 40-yard dash). But was he a physical freak, or a football player? Mays had five interceptions in 50 games at USC. Culliver had three picks in 43 games in college.

"After Taylor Mays, you're thinking, 'Is this another height-weight-speed guy?' " said Razzano, a scout for 24 years with the 49ers, Rams and Cardinals. "And (Culliver) is a height-weight-speed guy. But, so far, from what I've seen, he looks pretty good."

Indeed, unlike Mays, who was jettisoned to the Bengals in August for a seventh-round pick, Culliver appears to have a future in San Francisco.

Rookie cornerbacks are generally prime targets for opposing quarterbacks, but Culliver hasn't been picked on. In three games, quarterbacks have a 26.0 rating when throwing in Culliver's direction, completing 6 of 12 passes for 49 yards with no touchdowns and an interception.

Culliver started 32 games at South Carolina, but only seven at cornerback. Due to his inexperience, he appeared destined to spend a season on the sideline, learning the intricacies of the position.

Instead, it appears as if he's secured a spot as the No. 3 cornerback, moving ahead of eight-year veteran Shawntae Spencer on the depth chart. Cornerback Tramaine Brock, who could compete for the No. 3 spot, is out with a broken hand.

"He's got a bright future," defensive coordinator Vic Fangio said of Culliver. "If he continues to mature and become a pro football player from the mental aspect and how he approaches his profession, he's got a chance to be a really good defensive back in this league."

Kendall Hunter

Trailing the Eagles 23-17 late in the fourth quarter in Week 4, the 49ers faced third-and-7 from the Philadelphia 26.

In response, offensive coordinator Greg Roman called for the element of surprise. And he utilized an element of the offense that's been previously lacking in San Francisco: an effective running back behind Frank Gore.

That running back, rookie Kendall Hunter, took a third-down pitch and darted 14 yards around left end for a first down, setting up Gore's game-winning touchdown one play later.

"I'm not sure Gore's that kind of back," said NFL Films analyst Greg Cosell, recalling the play last week. "Hunter can get to the corner quicker."

Hunter, 5-foot-7 and 199 pounds, slipped to the fourth round of the draft because of concerns about his size and durability. But the 10th running back drafted ranks fifth among rookie running backs in yards from scrimmage (240).

Since 2008, the Niners have looked to the draft (Glen Coffee, Anthony Dixon) and free agency (DeShaun Foster) to find a suitable caddy for Gore. And it appears they might have finally found their man in Hunter, who scored the game-winning touchdown in a 13-8 win against the Bengals, jump-started a 20-point rally against the Eagles with a 44-yard catch-and-run and had the aforementioned third-down run on the game-winning drive in Philadelphia.

Hunter's 44-yard catch is the longest by a 49er this season. His season-best 44-yard run is the longest by a 49ers running back other than Gore since 2005. And his average of 8.7 carries over the past three games has provided a needed breather for Gore, who has reeled off three straight 100-yard games for the third time in his career.

"When you look at a back of that size, you assume he's just a finesse guy," said CBS Sports draft analyst Rob Rang. "But he showed at the Senior Bowl, and he's shown already in San Francisco, that he's a much more physical player than you'd generally think for a guy of his stature."

Bruce Miller

A few eyebrows were raised when the 49ers announced their intention to convert Central Florida defensive end Bruce Miller to fullback, a position he'd never played at any level.

But CBS Sports draft analyst Rob Rang wasn't among the skeptics. After watching Miller's all-out style of play in college, he figured it might translate to success at one of football's most physically demanding positions.

"I just remembered the physicality and the intensity with which he played in college," Rang said. "So I thought it made a lot of sense at the time."

Sure enough, the 49ers' gamble is looking quite logical.

With starting fullback Moran Norris sidelined by a leg injury, Miller, a seventh-round pick who began learning the position in late July, has assumed the fullback duties in the past four games. And, with Miller in the lineup, the 49ers have rushed for 200 yards in back-to-back games for the first time since 1998. In addition, Miller has flashed more athleticism than Norris, who has 11 receptions in his past 34 games. Miller has five catches for 40 yards.

Miller flashed his blend of aggression and athleticism on a 15-yard screen pass against the Eagles in Week 4. After catching the pass in stride, he finished by dropping his shoulder and leveling Eagles safety Nate Allen, displaying what offensive coordinator Greg Roman termed "violence on the boundary."

"He was one of those glorified try-hard guys who just didn't have enough skill for the NFL level," said NFL Films analyst Greg Cosell. "He was basically a 246-pound pass-rushing defensive end. He didn't have the quickness and movement to transition to 3-4 outside backer, so obviously he's transitioning to fullback.

"And he's given them really good snaps. I mean, really good snaps because Norris is out. Hey, I don't know what happens when Norris comes back. This kid's been an effective player."