NORMAN, Okla. — Mike Stoops is counting on a heavy dose of familiarity this season to help improve an Oklahoma defense that withered down the stretch a year ago.

Sooners coach Bob Stoops expects nothing less from the defense, or his younger brother in the second season of his second stint as defensive coordinator.

Despite winning 10 games for the third consecutive season last year, along with a share of the Big 12 championship, much of the Oklahoma's offseason has been filled with haunted memories of its second-half struggles on defense last season.

Some of those lowlights include allowing 34 or more points in four of its last five games, 41 or more three times — including in a 41-13 loss to Texas A&M in the Cotton Bowl. Heisman Trophy winner Johnny Manziel accounted for 516 yards of total offense (287 passing, 229 rushing) in that game, though he was hardly the only one to take advantage of the Sooners' late-season defensive woes.

"A year ago, there [were] a lot of games, it was a little bit like Dr. Jekyll and Mr. Hyde in that we had probably six or seven different games where we played really well, but we had a several that we played incredibly poor in," Stoops said.

"We've got to be more consistent defensively in our play. If we do, we'll have a chance to make good improvement and I believe we can."

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That consistency starts at the top, with Mike Stoops set to begin his second season back at Oklahoma after being fired as the head coach at Arizona midway through the 2011 season.

Stoops earned his reputation as a defensive coach in his first go-around with the Sooners, leading one of the top defenses in school history in 2000 — the last time Oklahoma won the national championship.

Last season, however, was anything but a defensive renaissance. The Sooners allowed nearly 400 yards and 25.5 points per game, numbers that on the surface weren't all that disappointing in the offense-charged Big 12.

It was how they gave up those yards and points that illustrated just how far Oklahoma had fallen in its final few games. The Sooners finished the season ninth in the Big 12 in rushing defense, allowing 192.2 yards on the ground per game.

They gave up an average of 5.2 yards per rush to opponents, and the lack of a true identity on defense left Stoops grasping for ideas at times.

"We were probably too predictable as the year went on in our inability to stop the run," Stoops said. "If you can't stop the run, it becomes very difficult to play good defense, and our inability to consistently stop the run down the stretch was frustrating.

"We want to make good on that, and certainly that will play into our chances to be in the thick of things, competing for another championship."

Oklahoma won five consecutive games entering the Cotton Bowl, but it relied heavily on its offense to overcome challenges from Baylor (42-34), West Virginia (50-49) and rival Oklahoma State (51-48 in overtime).

The most difficult game defensively — and unfortunately memorable for the Sooners — was the win against the Mountaineers. West Virginia gained 778 yards of total offense in the game, including a 344-yard rushing effort by Tavon Austin.

Stoops tried a variety of defensive looks to counter the Big 12's spread offenses, even leaving the linebackers off the field all together for stretches in favor of extra defensive backs. Nothing, however, worked as well as he would have liked.

"That was probably frustrating in a lot of different areas; personnel, coaching, everything kind of led into our collapse down the stretch," Stoops said. "It's something that we're very conscious of, want to make some improvements and adjustments in our style, in our play, in everything we do to be more multiple, be a little more diversified in our looks and our approach."

Oklahoma returns a host of experienced players on defense this season, led by cornerback Aaron Colvin. Despite replacing seven starters, the Sooners are counting on a talented secondary and group of linebackers, led by senior Corey Nelson, to make amends for last season.

They're also counting on an improved comfort level with Stoops in his second season back in charge of the defense.

"With the players that were here, the chemistry is just off the charts now," senior linebacker Corey Nelson said. "We're able to vibe with [the coaches]; we understand what they want and what they're looking for."