Halfway home in a season that has been full of surprises, the Dolphins are essentially back where they started:

They’re 4-4, a game out of the playoffs and just on the edge of national relevance, with some encouraging signs for the future but still plenty of questions about their present.

“I’m surprised too,” receiver Brian Hartline said when asked about the team’s expectations-busting start.

Hartline then added with a sly smile: “I thought we’d be 5-3.”

Here’s what is really shocking about a team expected by many to win no more than six games: With the right breaks and bounces here or there, the Dolphins could even be 7-1. Three of their losses have been by a combined nine points, and two came in overtime.

Then again, they could (and probably should) have lost at least one that they won (the Rams game comes to mind).

“We’re exactly what our record is,” Davone Bess said.

So as we pause, however briefly, at the midway point, let’s take a moment to remember from whence the Dolphins came — and what’s needed to get where they want to go.

OFFENSE

Statistically, the Dolphins look a lot like they did last season, when they were 22nd overall (317.4 yards per game) and averaged 20.6 points per outing. This season, they’re 23rd in total offense (332.5), scoring a shade more than three touchdowns each Sunday.

But at the most important position — quarterback — there’s no comparison. Ryan Tannehill looks like the real deal.

Through eight games, the rookie has completed 58.9 percent of his passes for 1,762 yards, with five touchdowns and six interceptions. He hasn’t turned the ball over since September, and — short of injury — will obliterate the team’s rookie passing record (2,210 yards, set by Dan Marino in 1983).

“The best thing about him is he’s getting better every week,” Bess said.

Matt Moore, last year’s starter, already has proved his worth as a backup. He completed 11 of 19 passes for 131 yards and a touchdown in relief, leading Miami past the rival Jets. Third-stringer Pat Devlin has not been activated for a game this season.

No one is happier about Tannehill’s emergence than Hartline, who already has more receiving yards (662 yards on 41 catches) than any previous year in his career.

Hartline and Bess (38 receptions for 483 yards) give Miami a potent one-two punch. But after that, production at the receiver position falls off considerably. Jabar Gaffney has caught three passes for 57 yards in two games since signing with the team in early October. Gaffney’s arrival has relegated Marlon Moore mainly to special teams, while Rishard Matthews hasn’t been in the mix.

The team’s No. 3 receiving option is Anthony Fasano. With three receiving touchdowns, he has half of the team’s scoring catches. Pro Football Focus ranks Fasano as the ninth-best tight end in football.

Charles Clay (six catches for 76 yards, one touchdown) has been largely invisible in the passing game, and Jeron Mastrud has taken just 56 snaps on offense all season. Rookie Michael Egnew is still waiting to see the field.

Miami’s running game started strong, but hasn’t done much in the past month. It has managed 111.9 yards per game — 13th in the league — and although Reggie Bush averages 4.4 yards per carry, he only gets about 15 runs per game.