Running backs

Reggie Bush and Daniel Thomas complement each other well, with Bush providing the speed and elusiveness and Thomas the bulk. Bush started fast and is on pace for a 1,000-yard season. But his rushing average is down from a year ago and he has not been the explosive mismatch as a receiver that some expected. Thomas has struggled with injuries and a couple of fumbles. His rushing average also isn’t extraordinary at 3.4 yards per carry. But he has done damage on screens and had good moments in goal-line situations. Lamar Miller is basically being redshirted so far. Grade: C.

Receiver/Tight end

The Dolphins have six passing touchdowns and that is tied for the fewest in the NFL. That doesn’t mean receivers are bad or the quarterback is bad. It means all of them have to pick up the pace because the NFL remains a passing league and wins are determined by which team scores the most touchdowns. That said, Brian Hartline is on his way to a career-best 1,200-yard season and Davone Bess could get close to 1,000. The Dolphins still need a third receiver option to emerge, whether its Anthony Fasano, Charles Clay or Jabar Gaffney. All three have had moments but none has been consistent enough to be a defense’s worry every week. The good news is this group has dependable hands. Dropped passes have been rare since Legedu Naanee was cut. Grade: B-minus.

Offensive line

Jake Long has not been elite this season. That doesn’t mean he has been bad, but he simply hasn’t played up to his previous levels. Left guard Richie Incognito was recently voted the NFL’s second-dirtiest player by a poll of his peers, but aside from that, he has neither been consistently great nor consistently poor. Mike Pouncey is consistently very good. He’s Miami’s best offensive lineman. Pouncey has taken John Jerry under his wing and the right guard has improved from the past two seasons. Jerry is still mostly an average player. Right tackle Jonathan Martin had a poor preseason and wasn’t very good early in the year, but he’s much better now and his ceiling is high once he gets stronger and more experienced. “There is some very good play from our offensive line,” Philbin said. “There is some okay play and there is some not very good, and that’s why I think we are 4-4. They’re part of that.” Grade: C-plus.

Defense

Is this unit very good or has the competition been so bad that it gives us a false read on the truth? Well, consider the Dolphins have played one game against a team (Houston) that is among the top 10 in scoring. They have played five games against teams ranked in the bottom third (20-32) of the league for points scored. That said, the Dolphins have been outstanding on third-down efficiency, excellent against the run and they have not surrendered a lot of points — indeed, they’re the sixth-stingiest unit in the NFL. Grade: B.

Defensive line

Cameron Wake has already equaled his sack total from a season ago (thank you, Bobby Massie!) and has been surprisingly good holding the edge on run plays. Paul Soliai has been a rock on the inside and Randy Starks is a fine combination of inside pass rush and good inside run defense. The rest is a work-in-progress. Jared Odrick is a good run defender but hasn’t developed his pass rush enough to turn the Pee-wee Herman dance into a staple. He has two sacks. Tony McDaniel has struggled staying healthy and durability is a crucial factor for players. Olivier Vernon is learning and his pass rush has slowly improved, but he’s a liability on run defense. In the second half, the one-man gang needs more help. Grade: B.