What happens when an unstoppable force meets an immovable object?
We'll find out Saturday night in Colorado Springs when the nation's No. 1 rushing offense clashes with the country's best run defense.
It's the Air Force Falcons, with their vaunted triple-option attack, against the San Diego State Aztecs, who know how to slow down the ground game.
"Air Force is always a dogfight every year when we play them," Aztecs cornerback Tayler Hawkins told the Denver Gazette earlier this year. "It's definitely a different type of game. You've got to come with your big-boy pads on when you play Air Force, for sure."
Yup, it's a big-boy game, alright. And there's plenty of big prizes on the line for the fight at Falcon Stadium.
The Falcons — at 6-1 overall — are trying to rise to 4-1 in Mountain West action, which would give them a stranglehold on the Mountain Division spot for the conference championship.
Meanwhile, the No. 22 Aztecs are hoping to remain perfect not only in conference play — in which they're 2-0 and looking to put one hand on the West Division berth for the Mountain West final — but in overall action this season. The Aztecs are 6-0 for only the second time in the past 46 years, and they'd like to stay in the AP Top 25.
So there is a lot on the line in this battle, including potentially home-field advantage for what could be a preview of December's conference championship.
No. 22 San Diego State at Air Force
Kickoff: Saturday, Oct. 23 at 7 p.m. ET
TV: CBS Sports Network
Spread: Air Force -3
When San Diego State Has the Ball
Brady Hoke is turning to Lucas Johnson to start at quarterback. This decision coming after Johnson took over for fellow senior Jordon Brookshire, who was banged up and ineffective, in the fourth quarter of last week's double-overtime win over the San Jose State Spartans. The 19-13 squeaker saw Johnson come in and complete two of three passes — both in OT and to receiver Jesse Matthews — for touchdowns.
"Lucas finished the other night on a high note," Hoke, the Aztecs head coach, told reporters. "He has the hot hand right now."
Well … he might be that in the what-have-you-done-for-me-lately department, but Johnson hasn't exactly had a large sample size on the season. He's 29-of-49 for 234 passing yards on the year, and he can run a little, with 88 yards on 15 carries for a sparkling per-game average of 5.9 yards.
Brookshire, meanwhile, went just 13-of-27 for 132 yards in the Week 7 win and is 40-of-84 for 521 passing yards on the season. He, too, can run a little, with 107 yards on 28 hauls.
But it's their backfield mates who make the San Diego State offense run smoothly as the 19th-best ground-moving crew in the country (215 ypg). Running back Greg Bell, in particular, is the go-to guy with 113 carries for 561 yards.
But even Nebraska transfer Bell was stymied last week against San Jose State's defense, and it won't get any easier against the D fielded by Air Force. It's allowing just 91.3 rushing yards per game. However, that perfect record sported by the Aztecs is no fluke. They know how to find the endzone when necessary.
"They move exceptionally well — they're large," Air Force head coach Troy Calhoun told reporters. "They're a really, really strong group. No matter what you use — any metric or just based upon the eye of the film — they are outstanding."
Junior kicker Matt Araiza is also outstanding, especially helping San Diego State with field position with his booming punts. His 86-yarder and perfectly placed 53-yarder helped set the table for last week's victory. He currently tops the nation with an average of 53.85 yards per punt. Araiza also had a career-long 53-yard field goal to help sink San Jose State.
When Air Force Has the Ball
Outstanding is an understatement when talking about the Falcons' rushing attack.
Nobody is better at running the ball than Air Force — 336 yards per game — with junior running back Brad Roberts ranked fifth in the nation with his 818 rushing yards. That's on 178 carries — 28 of them for 138 yards in last week's signature 24-17 victory over the host Boise State Broncos.
Junior QB Haaziq Daniels is also pretty effective with his feet, with 525 yards and a team-high nine touchdowns on 101 runs.
That triple-option puzzle has also seen wide receiver Micah Davis and sophomore running back Emmanuel Michel roll up 345 and 232 yards, respectively.
"This is definitely, definitely our biggest challenge of the year," Hoke told the Denver Gazette. "My (triple-option) background always has been you've got to stop the fullback. That's the first element."
Whatever the test, the Aztecs' defense has been up for it in 2021. The unit is a shade better than the Falcons' top-flight D, which has allowed an average of 288.7 yards a game. But of the 282.8 surrendered, it's the run-stuffing, which has been of particular note for San Diego State. It's No. 1 in the FBS, giving up just 61.2 rush yards a contest.
The defense — anchored by safety Patrick McMorris' team-leading 40 tackles and 3.5 sacks from both lineman Cameron Thomas and linebacker Caden McDonald — is a big reason why Hoke's team boasts that perfect record.
When the Falcons throw the ball, QB Daniels is 23-of-48 for 553 yards.
The win over Boise State was a big one, boosting the confidence of Air Force in preparing for another biggie here.
"It's trite — and I say it over and over — but it's one game," Calhoun told reporters last weekend. "We need to enjoy this one, but we need to get better and have some things we need to fix. We made a good number of mistakes, but we hung in there and persevered."
They'll need a similar effort against perfect San Diego State, which represents another chance to beat a ranked opponent. Air Force has lost four straight to AP Top 25 teams since 2016.
Regardless, it's most likely to be a tight one decided late or even in overtime, with not much separating these teams except for Air Force's triple-option approach to offense.
They are both stingy teams, surrendering only 16 points a game. And the Aztecs hold a slight edge on the scoreboard, having averaged 33 points a game against 31 for the Falcons.
No matter how you slice it, this Mountain West monster is shaping up to be a can't-miss crash-and-bang game.
Prediction: Air Force 23, San Diego State 20
Podcast: Previewing Week 8 + CFB Expansion + Washington State Coaching Search