QUARTERBACK

Ryan Tannehill had a first down at the San Francisco 35-yard line in the fourth quarter and the Dolphins down by a touchdown. He threw four consecutive incomplete passes. Ballgame. He doesn’t consistently make plays in critical late situations, and that’s one reason the Dolphins offense cannot get over the hump. By the way, Tannehill often makes similar plays earlier in the game, but that’s when they are not nearly as critical. It must be said he avoided the big mistake interception. GRADE: C-minus.

RUNNING BACK

Reggie Bush had a typical game. Fourteen carries for 65 yards will get a running back close to 1,000 yards for the season but it isn’t nearly enough to make a significant difference. The Dolphins did use Bush out wide in this game more than they had all season. But Bush dropped one of the passes while catching five for 38 yards. Lamar Miller was used ahead of Daniel Thomas, who didn’t enter the game until a fourth-quarter red-zone situation. Three attempts for Miller are not enough of an opportunity to make a difference, however. GRADE: C.

RECEIVERS/TIGHT ENDS

Brian Hartline started fast with a 28-yard catch in the first half, but he caught only one pass on the next seven targets. He did draw a pass interference penalty. Davone Bess had a typical game for him (five for 50 yards) but nothing extraordinary outside a 21-yard catch. He also had a fumble. Anthony Fasano delivered the catch of the day — perhaps the year for a Miami pass-catcher — when he dove, one-handed a pass in the corner of the end zone, and got his knee down in time to make it count. GRADE: C.

OFFENSIVE LINE

Another week, another Mike Pouncey pancake block, this one on a screen. He was mostly good. Jonathan Martin struggled in his first NFL start at left tackle. He yielded two sacks and had a false-start penalty. But it should not go unnoticed that Martin was matched against NFL sack-leader Aldon Smith most of the day. Right tackle Nate Garner also had a false start, but he didn’t give up any sacks. The interior of the Dolphins line was surprisingly effective against one of the best defensive fronts in football, as Miami averaged 4.3 yards per rush. GRADE: C-plus.

DEFENSIVE LINE

Cameron Wake was the best pass rusher in the game, as he overshadowed Smith. Jared Odrick also got into the act and it should be noted that, unlike last week, both Wake and Odrick were in the game late when it mattered most. The interior of the Miami line had a nice fourth-down stop, but also was shredded by Frank Gore on a couple of inside runs. And where was the containment on the Kaepernick 50 yard run? GRADE: B-minus.

LINEBACKERS

Karlos Dansby led with 12 tackles, including two for loss. Kevin Burnett got beat by Vernon Davis on the first series of the game but helped to shut him down the rest of the day, so fine work there. There were, however, too many missed tackles as Gore turned what should have been a 5-yard run into a 19-yard run. And where was the tackle on what turned into a 50-yard TD run by Kaepernick? GRADE: C-plus.

SECONDARY

Michael Crabtree had too much room all day long. He let Miami defensive backs overrun tackles and that turned 5- or 6-yard passes into first down catches. If Kaepernick were a better quarterback, he would have targeted Randy Moss more often because he was open a lot, particularly deep. Moss did drop a potential TD pass over R.J. Stanford. Stanford interfered but it wasn’t called, so great job by him. Sean Smith, meanwhile, was called for a pass interference that was questionable. But it was called, so bad job by him. Chris Clemons had a dumb roughing penalty. GRADE: C.

SPECIAL TEAMS

Marcus Thigpen fumbled a punt that led to a 49ers’ touchdown and linebacker Jonathan Freeny turned a great punt by Brandon Fields into a touchback when he allowed his momentum to carry him to the goal line. Dan Carpenter was excellent, delivering a 53-yard field goal. GRADE: D.

COACHING

They tried to see whether Lamar Miller could be a spark but gave him only two carries, so good idea but poorly executed. They tried to use Reggie Bush out wide to create a mismatch against a linebacker, but Bush dropped one pass and averaged only 7.6 yard per catch. Joe Philbin’s staff tried things. None ultimately made a difference in the outcome. C-plus.

OVERALL

Not. Good. Enough. GRADE: D.