FORT WORTH, Texas – TCU coach Gary Patterson is known for his innovative 4-2-5 defense. He’s had to develop something a bit different in order to survive this season.

“We’re not playing 4-2-5 right now,” he joked. “We’re playing 4-7.”

He has two former safeties starting at linebacker. Two corners on the outside. Three more safeties patrolling the field. And four of the seven happen to be underclassmen who’d never started a game for the Horned Frogs going into the season.

In all, TCU already has 20 defenders who’ve started at least one game in 2015. For all the close games, injuries and growing pains, they still found a way to reach 7-0. They head into their Thursday night showdown with West Virginia fresh off a bye and two weeks of encouraging developments. The signs that the Horned Frogs are improving under fire can be found in their recent second-half success.

Kansas State’s offense, thoroughly dominant in a 35-point first half, produced just 129 yards and 3.6 yards per carry the rest of the way in TCU's 52-45 comeback win. Joe Hubener was 5-of-18 through the air in the second half and the Wildcats were 3-of-8 on third downs.

A week later in Ames, Iowa, TCU was mired in a back-and-forth, 21-21 ballgame until defensive end Mike Tuaua fell on a fumbled option pitch in the red zone midway through the second quarter. From there on out, the Frogs pitched a shutout and held the Cyclones to 4.2 yards per play and 3.1 per rush in a 45-21 win.

“You’ve got to give our kids credit: They’ve made mistakes, but they’ve made stops when they needed to,” Patterson said. “Do we need to start faster? Would we rather they play like they did against Texas every week? Yeah. But if it was that easy, everybody would be undefeated and everybody would be playing great defense.”

A week before Tuaua helped flip the Iowa State game, another turnover -- a pick-six from Derrick Kindred -- got the comeback started against Kansas State. The senior safety knows TCU’s production is down in the takeaway department -- they had 21 through seven games last season but only 10 in 2015 -- but he’s not surprised considering all the youth on the field.

“That just comes with a lot of guys new to the game. A lot of freshmen, a lot of first-time players,” Kindred said. “They’re learning how to track the ball and just trying to not give up big plays.”

They’re just trying to get comfortable, too. Against K-State, TCU got to play the same starting lineup on defense in back-to-back weeks for the first time all season. Then it changed again the next week.

Four different players have earned starts at weak safety. One of them, sophomore Nick Orr, went from corner to safety and back to corner. TCU has relied on three different starters at right end and at middle linebacker, too.

Some of Patterson’s defenders are developing such positional versatility (by need, not choice) that when strong safety Denzel Johnson was ejected for targeted against Iowa State, safety-turned-linebacker Travin Howard went back to safety and TCU inserted Ty Summers at linebacker.

TCU did sign 12 defenders in February. Nine have already seen the field. They don’t know what they don’t know, and they’ve had to learn (and relearn) quickly.

“Every day is ‘50 First Dates’ sometimes,” Patterson said.

To ensure this defense and this season don’t end up like one of the more unfunny Adam Sandler films, they must keep growing. We’re now exactly one month away from the Baylor-TCU rematch on Nov. 27, and TCU still has to play four more games before we get there.

The defense that takes the field against the Bears won’t share much in common with the one that almost won last year’s shootout. But different as this 4-7-ish D might look, Patterson is starting to like how it’s shaping up.

“I’ve got plenty of things to find out we can get better at,” Patterson said, “but right now I should just appreciate they’ve played their tails off.”