Midseason report card: How has Boise State fared through six games this season?

This season has already been a roller-coaster ride for the Boise State football team.

Former Boise State linebacker Andy Avalos’ second season as head coach began with a disappointing loss at Oregon State. The Broncos hit rock bottom a few weeks later after a loss to 15-point underdog UTEP.

Offensive coordinator Tim Plough was fired less than 24 hours after the loss to the Miners, and four-year quarterback Hank Bachmeier opted to transfer a few days later.

Former Boise State and Tampa Bay Buccaneers head coach Dirk Koetter took over the offense, and athletic redshirt freshman Taylen Green took over at quarterback.

Change is never easy, but it has worked for the Broncos (4-2, 3-0 MW). They’ve won back-to-back games, and they’re the only team in the Mountain West that is undefeated in conference play heading into Saturday’s showdown at Air Force (5 p.m., CBS Sports Network).

“It’s been awesome to see how the whole team has come together and the energy, faith and enthusiasm that comes with that,” Avalos said Monday.

Here’s a look at how the Broncos have performed through six games this season.

Offense: B-

Boise State’s offense had no rhythm or clear identity early in the season, but that changed when Koetter and Green took over heading into the Broncos’ 35-13 win over San Diego State.

The Broncos averaged 120.2 rushing yards and 22 points a game through the first four contests. They’ve since racked up exactly 316 yards on the ground twice and scored a combined 75 points in wins over San Diego State and Fresno State.

Much of that newfound success can be attributed to Green’s freakish athleticism, which helped him run for more than 100 yards against Oregon State and San Diego State. The 6-foot-6 native of Allen, Texas, leads the team with four rushing touchdowns, and he’s third with 229 yards on the ground.

Koetter also deserves a major tip of the cap for the Broncos’ offensive turnaround. The veteran of more than three decades in the coaching profession has shown that he knows how to mold his scheme around the strengths of his players and adjust on the fly. Both are critical to a coach’s success.

Boise State’s running game has flourished under Koetter’s direction. Redshirt junior running back George Holani and freshman Ashton Jeanty have joined Green to form a three-headed monster that has a whole lot of defensive coordinators feeling nervous.

Holani has rushed for more than 100 yards in each of the past two games, and he leads the Broncos with 549 yards and three touchdowns on the ground. Jeanty posted the first 100-yard rushing game of his career in Boise State’s 40-20 win over Fresno State, and he’s second on the team with 310 yards and three touchdowns.

The running game is thriving, but the Broncos’ passing game still needs major work.

A true No. 1 receiver has not emerged, and there isn’t a receiver on the roster that has been getting consistent separation from defenders. The Broncos rank No. 8 in the Mountain West, averaging 152.2 passing yards a game.

Redshirt freshman Latrell Caples leads the Broncos with 18 catches for 171 yards. Stefan Cobbs ranks No. 2 with 17 catches and No. 3 with 144 yards. He and Caples are tied with two touchdown catches, but Holani leads the team with three.

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Defense: A

There have been a couple hiccups by the defense, including surrendering 199 rushing yards against UTEP. But there aren’t many gripes to be found about a unit that not only ranks as one of the best in the Mountain West, but in the country.

Boise State leads the country in pass defense, allowing just 134.3 yards a game. The Broncos also lead the conference and rank No. 2 in the country in total defense, giving up 236.2 yards a game. Illinois leads the country, surrendering 221.1.

The Broncos also own the Mountain West’s top rushing defense, allowing just 101.8 yards a game. They’re giving up 19.2 points a game, which ranks No. 3 in the conference.

Linebacker DJ Schramm leads the Broncos with 49 tackles, and Weber State transfer George Tarlas leads the team with four sacks.

If there is a gripe to be found on defense, it’s Boise State’s inconsistency when it comes to forcing turnovers. After forcing three in the season opener at Oregon State, the Broncos earned just two takeaways in the four games that followed.

The Broncos came up with two big interceptions against Fresno State, but with five picks and two fumble recoveries through six games, the unit is not on pace to match the 23 turnovers Boise State forced last season.

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Special teams: C-

Kicker Jonah Dalmas rebounded nicely after missing two field goals in the season opener. He hasn’t missed since, and the former walk-on has been named Mountain West Special Teams Player of the Week twice: after he went 3-for-3 against UT Martin on Sept. 17, and following a 4-for-4 performance against Fresno State on Oct. 8.

Freshman punter James Ferguson-Reynolds has been inconsistent, but he’s averaging a respectable 43.1 yards per punt.

The area of concern for the Broncos’ special teams is in the return game. Wide receiver Cole Wright’s 36-yard kickoff return against UT Martin is the most explosive play by a Boise State returner this year.

The Broncos have also given up three special teams touchdowns: a blocked punt that San Diego State turned into seven points, a 47-yard punt return at UTEP and a 100-yard kickoff return at New Mexico.

BOISE STATE AT AIR FORCE

When: 5 p.m. Saturday

Where: Falcon Stadium (46,692), Air Force Academy, Colorado

TV: CBS Sports Network (Rich Waltz, Aaron Taylor, Sherree Burress)

Radio: KBOI 670 AM/93.1 FM (Bob Behler, Pete Cavender)

Records: Boise State 4-2, 3-0 MW; Air Force 5-2, 2-2 MW

Series: Boise State leads all-time series 6-4, but the Falcons beat the Broncos 24-17 at Albertsons Stadium last season.

Vegas line: Air Force by 3

Weather: High of 70 degrees, 0% chance of rain, 12 mph wind