Grading the 49ers rookies: One clear hit in a good class that could get better

San Francisco 49ers defensive lineman Romello Height, left, and safety Malik Mustapha after a stop against the Denver Broncos on Oct. 4 at Levi's Stadium. (Stephen Lam/S.F. Chronicle) The San Francisco 49ers, 6-1 at their Week 8 bye, owe a not-so-insignificant part of their early success to a handful of rookies.It's not the strongest draft class of all time. The group lacks top-end talent. No surefire star has emerged. Its top selection, wide receiver De'Zhaun Stribling, has been out with an ankle injury since Week 1.But a quartet of unheralded mid-round picks has largely impressed onlookers through seven weeks. All four were selected in Rounds 3 through 5, and each has either carved out a starting role or become a key rotation player for one of the NFL's best teams. Not too shabby, John Lynch.The Chronicle is handing out midseason-ish report cards to Romello Height, Kaelon Black, Gracen Halton and Jaden Dugger. Players who won't receive grades because of insufficient playing time: Stribling, guard Carver Willis, cornerback Ephesians Prysock, tackle Enrique Cruz Jr. and defensive tackle James Thompson Jr.EDGE Romello HeightLynch drafted Height, 25, expecting him to be an NFL-ready contributor from Day 1. The early returns suggest he was right.The No. 70 overall pick leads the Niners' defensive line in pressure rate (10.4%) and ranks second in pass rush win rate (7.9%) behind Keion White, according to Next Gen Stats and Sumer Sports. Nick Bosa technically leads the 49ers in both categories, but the All-Pro defensive end has played just two games.Inside the 49ers' facility, Height has gained a reputation for owning a revved-up motor. He works through the whistle and uses his 6-foot-2, 239-pound frame to fly off the edge as a speed rusher. His lack of size hurts him in the trenches, however, which is why only 30% of his snaps have come as a run defender.Height also deserves credit for adapting on the fly.He had to adjust his playing style two weeks into his NFL career after he broke his right hand against the Miami Dolphins. He has since played with a massive club, requiring him to alter his pass-rushing technique. Height said he hopes to shed his cast after the bye week. Height's numbers through six games aren't eye-popping: He has eight total tackles, five quarterback hits and 1.5 sacks. But he has become a reliable rotation option for a banged-up defensive line, good enough for an early success story in Round 3.Grade: B San Francisco 49ers running back Kaelon Black has largely struggled since a standout debut against the Rams, but he still has time to prove his value as a third-round pick. (Stephen Lam/S.F. Chronicle) RB Kaelon BlackLynch has earned a reputation for whiffing on mid-round running backs. Third-round picks Trey Sermon and Tyrion Davis-Price come to mind, while Isaac Guerendo, a 2024 fourth-rounder, hasn't panned out, either.So it was fair to question the selection of Kaelon Black with the No. 90 overall pick in April's draft. The now-25-year-old was aware of the popular narrative. He entered training camp competing with Jordan James for the No. 2 spot and won the job.Through seven games, Black's results have been mixed: 57 carries for 4.1 yards per attempt. He looked the part in Week 1, shouldering 14 carries for 65 yards while keeping Christian McCaffrey fresh for the fourth quarter. But he has largely struggled since.Black broke free for a 30-yard touchdown run, his first of the season, Sunday against the Atlanta Falcons. He also fumbled. From Weeks 2 through 6, he never gained more than 37 yards in a game or ran for more than 4.3 yards per carry. Against the Seahawks and Broncos, he had 12 combined carries for just 29 yards. Black runs extremely hard, but he has struggled with his vision. After the Week 1 win in Australia, tackle Colton McKivitz joked that he needed Black to stop running directly into his back. In Week 6 against the Washington Commanders, Black popped George Kittle, his helmet crushing the back of his tight end's knee in what could have resulted in a dangerous injury.It wasn't a catastrophic selection, but the 49ers could have done better at this spot - and/or used a different method to find a backup running back. Black still has time to prove the pick was the right one.Grade: C Defensive tackle Gracen Halton (93) pressures Miami Dolphins quarterback Malik Willis on Sept. 20 at Levi's Stadium in Santa Clara. Halton stands to benefit from the arrival of DeForest Buckner. (Santiago Mejia/S.F. Chronicle) DT Gracen HaltonThis could end up being the best value pick of the 49ers' 2026 class. Despite being undersized for a defensive tackle at 6-foot-2 and 293 pounds, Halton has been arguably the most productive rookie at his position. His nine solo tackles and two sacks lead all first-year interior defensive lineman, while his 6.7% pass-rush win rate ranks third, per Sumer Sports.The Oklahoma product flashed his upside in a dominant performance against the Seahawks. Halton forced a fumble and recovered it for a touchdown while recording a sack, a quarterback hit and two tackles-for-loss.Selected No. 107 overall in the fourth round, Halton was the 12th defensive tackle taken.Niners defensive tackle Osa Odighizuwa, for one, is a big fan of Halton. He said the rookie's quickness and athleticism "popped immediately" when he arrived in the spring. What has improved immensely since then, Odighizuwa added, is his technique."As his technique starts to sharpen, it lets all the athletic ability shine even more," Odighizuwa told the Chronicle. "Gives you a lot of hope about his upside and how high his ceiling is."With DeForest Buckner now in the fold alongside Odighizuwa, life figures to get easier for Halton. He might not start, as he did in six of the 49ers' first seven games, but he should have plenty of opportunities alongside two players who attract double teams.Grade: A Linebacker Jaden Dugger's versatility is a gift to 49ers defensive coordinator Raheem Morris. He should only get more comfortable as the season progresses. (Danny Karnik/Associated Press) LB Jaden Dugger A fifth-round inside linebacker carving out a starting role as a rookie? Say hello to the next Dre Greenlaw, 49ers fans (maybe).The comparison isn't that simple. In fact, Dugger and Greenlaw are polar opposites in some ways. The 22-year-old rookie, listed at 6-foot-5 and 242 pounds, needs to fill out his frame to match his freakish 7-foot wingspan. Greenlaw is a compact 6-foot, 230-pound wrecking ball. On the field, Dugger is emotionless, bordering on mute; Greenlaw is explosive and expressive.Nonetheless, Lynch appears to have found another gem of a linebacker on Day 3 of the draft. Dugger, viewed as a raw prospect entering April, has played more than half of San Francisco's defensive snaps this season, according to Pro Football Focus. He has recorded 30 tackles, two tackles for loss, one sack and one quarterback hit, primarily playing the "fever back" role in defensive coordinator Raheem Morris' scheme. That means he is able to play in coverage or off the edge as a pass rusher (which he has done only 21 times).When Greenlaw missed the Commanders game, Dugger filled in admirably, recording a career-high 11 tackles. He had seen limited time at Greenlaw's weak-side linebacker spot before then.Dugger's versatility is a gift to Morris. He should only get more comfortable as the season progresses, assuming he gets to keep playing alongside a healthy Greenlaw and Fred Warner.Grade: A-Overallgrade: BThe lack of a cornerstone player brings down the overall grade, but Lynch deserves credit for doing good work in the middle rounds once again, especially on the defensive side of the ball.Between the 49ers' 2025 and 2026 draft classes, they have six key defenders on this year's roster: Height, Halton, Dugger, safety Marques Sigle, nickel back Upton Stout and defensive end Mykel Williams.The rookie class could soon get a boost, too. Stribling, who impressed during the preseason and was expected to play a significant role in the 49ers' offense before his injury, is expected to return sometime in December.SubscribeThere’s more to San Francisco with the Chronicle. Subscribe today for just 25¢.This article originally published at Grading the 49ers rookies: One clear hit in a good class that could get better.