Fourth-and-1 at Texas Tech's 39. Time for the Red Raiders, down seven points in the third quarter, to get a stop.

Arkansas lined up exactly how you would expect: A three-tight-end power set with a fullback. Nine blockers, one running back. No pass, no fakes, no funny stuff. Just a power run off right tackle. And Texas Tech played it right.

Safety J.J. Gaines met Arkansas back Jonathan Williams near the line of scrimmage. Williams juked left. Gaines whiffed. Then the Arkansas junior threw two stiff-arms at linebacker Sam Eguaoven and picked up 21 yards. Six plays later, the Hogs were back in the end zone.

This wasn't the turning-point play in Texas Tech's 49-28 loss. Just another landed punch in an eventual beatdown.

Williams ran for 80 yards in the second half, teammate Alex Collins added 167 yards, Arkansas averaged a ridiculous 7.15 yards per carry and attempted just two passes. No need to throw. Everything was working against a Red Raiders defense whose biggest flaw of 2013 re-emerged.

"You've got to give them credit," Texas Tech coach Kliff Kingsbury said after the loss. "They lined up and pounded us, and we just didn't have an answer today."

Fixing a Texas Tech run defense that has been a sieve in its past nine games is Challenge No. 1 for newly elevated defensive coordinator Mike Smith. Though Matt Wallerstedt exited Thursday because of off-field issues, he leaves behind one real on-field problem that Big 12 foes will try to exploit.

Since Oct. 26, 2013, Tech's first loss of last season at Oklahoma, the Red Raiders have the second-worst run defense in the FBS at 293.4 rushing yards allowed per game.

During that nine-game stretch, of which Tech has lost six, no defense in the country has given up more first downs on rushes (142). Only Southern Miss has allowed more touchdowns and more rushes of 10-plus yards.

In fact, Tech gave up 36 rushing touchdowns during that period, eight more than any other FBS team.

Though Arkansas has one of the best run games in the country, a power-heavy attack the likes of which Tech probably will not face again in Big 12 play, the fact is no FBS defense has faced more rushing plays in those nine games than Tech. Opponents know they must hit this weak spot hard. The Red Raiders know it's coming. They can't stop it.

In the third quarter against Arkansas, Williams' fourth-down dash was deadly because it was another play that kept Texas Tech’s defense on the field. The Hogs ran 23 plays in the quarter and kept the ball for a total of 12:45. That is an easy way to get your opponent gassed.

Linebacker V.J. Fehoko said he saw too many communication issues, too many times when defenders tried to do too much and didn't stick to their assignment.

"In this conference," Fehoko said Saturday, "the smallest mistakes go the longest ways."

Though this is a generally young defense, the starters in the front seven are all juniors and seniors. How are they going to react to another letdown against the run?

"You know, it's tough. It's tough when the ball's not going your way and the momentum's not going your way," Fehoko said. "But I think we've got to just persevere and fight through it. As a team we've got a lot of young guys, but that's no excuse. I think energy and fire comes from within."

So does Texas Tech's new leadership on defense. Smith was already the co-coordinator, so it's not a drastic change. He is expected to bring more of an NFL mindset to assignment and alignment than Wallerstedt. And no doubt he's already hard at work to address his defense's most obvious defect.

It's not that complicated. Next up is Oklahoma State. They and every other opponent are going to pound the rock. They will keep doing it, and the reputation will continue, until Texas Tech starts finding answers to stop it.