Oklahoma's dominant defense continues to improve

After last season's defensive problems, this year's continues to show its dominance for Oklahoma.

NORMAN, Okla. -- At some point, quarterback Blake Bell won't be as good as he has been.

There has to be some regression coming. It's only natural. And with Notre Dame behind the Sooners and Texas ahead, this week against TCU sure sets up for the perfect opportunity for a letdown.

It may happen, but it's not likely, but what's even less likely is the Sooner defense stumbling – not after what it's taken to get where they are now.

All they have done is improve after back to back seasons where all they did was fall apart.

And then all the defense did was show it's a lot better than anyone expected in a victory over Notre Dame.

"We learned that we can play," said defensive end Geneo Grissom. "Everybody was saying it was a statement game. It was. To get a win there is an accomplishment."

It's not an accomplishment. It's a shock, considering how this defense was bad against OSU, worse against West Virginia and then embarrassed against Texas A&M a year ago.

The Sooner defense scored twice in the first 3 minutes against Notre Dame and upped its takeaways to nine on the season. So far, OU has scored 42 points off of turnovers this season while not allowing more than 21 points in any of the first four games.

Not bad considering the defensive line is reworked with all sorts of new faces, the defensive backs are young and the linebackers are back in a situation they didn't see a season ago.

"What I hoped to see was a team that handled itself with poise," coach Bob Stoops said. "Which we did. I can't say I wasn't expecting it."

The rest of us can, that's for sure.

C'mon did you expect the OU defense to be the Big 12 leader in pass defense, third-down defense and second in the conference in rushing defense? Be honest.

The result has helped steady a team that wasn't crisp offensively in the first two games, and helped support a team that has scored 86 points the past two weeks.

"We're progressing," Stoops said. "We know we've played pretty well in four games. We're nowhere near a finished product."

But more importantly, they are nowhere near where they were a season ago.

Charles Tapper, Jordan Phillips and Grissom – all consistent starters for the first times in their career have been outstanding on the defensive line. Zack Sanchez is a first-year starter at corner. Gabe Lynn has switched positions to free safety effectively and has two interceptions. Eric Striker at linebacker had the hit that led to Corey Nelson's interception and a touchdown against the Irish. Linebacker Frank Shannon has 27 tackles.

Through three weeks the Sooners allowed just 27 points total. Through four weeks, despite allowing a modest 21 points, the Sooner defense proved itself.

"I knew we would learn a lot about ourselves playing a team like that," defensive coordinator Mike Stoops said.

The rest of us learned something, too. This isn't the same defensive effort we've seen the past two years. This isn't the same Mike Stoops defenses that finished No. 7 or better nationally in scoring defense four times and in the top 10 nationally in total defense four times, but there's been a lot of progress made.

"It starts with players with a good scheme, executing," Striker said. "Keep that chip on your shoulder. Stay humble."

Follow Andrew Gilman on Twitter: @andrewgilmanOK