It could have been a seminal moment for Texas Tech’s defense and its seemingly never-ending quest toward respectability.

With third-ranked TCU facing fourth-and-goal and down to its final play, the Red Raiders had a prime opportunity to land the biggest win of the Kliff Kingsbury era while catapulting themselves into the Big 12 title conversation.

Instead, Trevone Boykin's desperation pass bounced off Josh Doctson's hand and into the arms of diving running back Aaron Green, robbing Tech's defense of a signature moment while giving the Horned Frogs the improbable game-winning score.

“We had TCU down to fourth down, we could say that we deflected the pass,” defensive coordinator David Gibbs said in a recent phone interview with ESPN.com. “At the end of the day, we’ve got to make those plays."

Finally having the benefit of stability, the Red Raiders defense is hopeful it'll begin making more of those plays in 2016.

Ever since then-coach Mike Leach fired defensive coordinator Lyle Setencich in the middle of the 2007 season, the Red Raiders have endured tumultuous times not only unearthing an identity defensively, but finding a coordinator to stick long enough to implement one. When Gibbs was hired last year to replace interim coordinator Mike Smith, he remarkably became Tech's seventh defensive coordinator in as many years.

Gibbs' arrival didn't lead to instant success.

The Red Raiders finished next-to-last nationally in run defense and total defense, and 125th in scoring defense. Tech, in fact, surrendered at least 44 points eight times in its 13 games.

"Obviously we were terrible," Gibbs said. "We were bad in every category."

But having a coordinator back for a second season could also do wonders for the Red Raiders, who bring back seven starters defensively.

“Anytime you can keep the same terminology, the same players, you've got to be better,” Gibbs said. “We were so bad, how much better we’ll be, I don’t know. But I’m glad to be back for Year 2."

Offensively, Tech graduated a pair of stars in running back DeAndre Washington and receiver Jakeem Grant. But behind standout quarterback Patrick Mahomes, the Red Raiders could be as dangerous as ever offensively next season after ranking second nationally in scoring last year.

"Our offense is dynamic," Gibbs said. "Our offense can match up with any other offense out there. It's up to our defense to stop people enough to win games."

The Red Raiders could be better equipped to do that this season. One reason is Breiden Fehoko, a former prized signee (No. 51 in ESPN 300) who started every game at defensive tackle as a true freshman in 2015. In the mold of former Baylor Big 12 Defensive Player of the Year Andrew Billings, Fehoko has tremendous strength for his age. If he too can develop into an all-conference-caliber defensive lineman, that could do wonders for a run defense that for years has longed for a difference-maker on the interior.

"It starts and ends in the trenches," said Fehoko, who noted he watches film of Billings every week to learn from him. "I feel confident I can be that player my team needs me to be to help change the game."

Fehoko should have more help up front, too. The Red Raiders will add a pair of intriguing eligible transfers to the front in defensive tackle Ondre Pipkins (Michigan) and defensive end/linebacker Kolin Hill (Notre Dame).

On top of that, the Red Raiders boast three experienced linebackers in Dakota Allen, Malik Jenkins and D'Vonta Hinton. The entire two-deep of the secondary is back, as well, though Gibbs has opened up competition across the board in an attempt to get his best tacklers on the field.

Of course, none of this means Tech will suddenly morph into a juggernaut defensively. Gibbs acknowledges the transformation won't happen overnight. Instead, he's focused on gradual improvement over instant perfection.

"Our kids are still learning the culture. That takes time," Gibbs said. "I could say we're going to finish in the top tier [defensively]. That's not a goal we can achieve right now, in my opinion.

"We're on the way up. But right now, we want to give our great offense the ball and have a chance to win all 12 games. That's something that hasn't always been the case."