NAPA – Not long after Dennis Allen became the new head coach of the Raiders, and Jason Tarver his defensive coordinator, the two sat down to begin fashioning the defense the Raiders will run this season.

This, as Tarver tells it, was a detailed process that involved the entire defensive coaching staff. With the franchise still in flux following the death of longtime owner Al Davis last season, they were painting on a blank canvas.

"We went in and said, 'Hey, we don't have every answer. We've got a few decent answers, but let's come up with the best. Let's come up with the Raider defense,' " Tarver said. " 'What do we want it to look like, starting from scratch? How do we huddle? How do we move around on the field? How do we communicate during a no-huddle?' You name it, it was all discussed."

For Allen, the Raiders' first head coach to come from a defensive background since John Madden in 1969, collaboration was important. New general manager Reggie McKenzie, himself a former linebacker, arrived this offseason proposing the Raiders try to "win on defense." And if Allen's staff was going to teach a new scheme, he felt they needed to have some ownership of it.

"This wasn't, 'Here's the playbook, learn it,' " Allen said. "We tore it all apart, went back all the way to the basics and built it from the ground up, based on the concepts we felt like were going to give us a chance to be successful."

Allen and Tarver are now tasked with improving a defense that has ranked in the bottom half of the NFL in points allowed every year since 2002 – the last season the Raiders made the playoffs.

In 2011, the Raiders struggled against the run (NFL-high 5.1 yards allowed per carry) and the pass (251.4 yards per game, 27th overall), proved susceptible to the big play and contributed to the team setting a record for most penalties and penalized yards in a season.

Few specifics have been shared about the new defensive scheme, with coaches and players only hinting at themes. The Raiders will be more "multiple" with their defensive alignments. They will blitz from different angles, incorporating linebackers and the secondary.

They will mix some zone in with their man-toman coverage, allowing cornerbacks to read the quarterback and look for interceptions.

"It's a new philosophy, man," said safety Tyvon Branch, a Pro Bowl alternate last year. "We're going to do a lot more stuff as far as pressures and things like that. ... It's not just line up and guard your guy."

Free agents are the new cornerbacks Despite their defensive shortcomings last season, and a midseason quarterback change in which Carson Palmer came off his couch to Oakland after a trade, the Raiders finished 8-8 and were within a Week 17 win of making the playoffs as the AFC West champion.

That in itself was encouraging coming in, Allen said.

"Obviously, we looked at the talent on the team and felt like there was talent," Allen said. "We didn't feel like the cupboard was bare."

Turnover on defense has been limited. The Raiders jettisoned their starting cornerbacks and signed Ron Bartell and Shawntae Spencer, veterans who share a birth date and have brought a steady presence into camp coming off years in which they hardly played because of injury (Bartell) or falling off the depth chart in San Francisco (Spencer).

At linebacker, newcomer Philip Wheeler, signed from Indianapolis to replace Kamerion Wimbley, has pleasantly surprised coaches with his versatility on the strong side, while rookie Miles Burris, a Granite Bay High School graduate who played at San Diego State, is undergoing a crash course in the NFL game on the weakside with veteran Aaron Curry battling knee problems.

Veteran tackles Richard Seymour and Tommy Kelly anchor the line, and the return of end Matt Shaughnessy, who missed 13 games last season with a shoulder injury, should help the Raiders shore up their run defense. Middle linebacker Rolando McClain can help as well by filling gaps and fulfilling the potential that made him the 10th overall draft pick in 2008, and also is being asked this year to be a more vocal leader on defense.

Just how much better the defense can be with much of the same personnel remains to be seen. Allen comes from Denver, where in one season as defensive coordinator he coaxed some improvement out of a unit that had nowhere to go but up. The Broncos, last in the NFL in 2010 in yards and points allowed, finished 20th and 24th in those respective categories last season and won a playoff game.

Seymour came into camp proclaiming that the Raiders can be one of the NFL's better defensive teams this season, using the admittedly optimistic term "top five." It's a belief that has since been echoed by several veterans on the defense, including Kelly, who said the reason for his sunny outlook is the attention to detail by Allen and Tarver.

"You see the mental errors on the field, on the practice field, even in the game, they were down," Kelly said. "We can fix the technique. "But we cut down on the mental errors and the penalties, man, people are going to have a hard time dealing with us."

The Raiders last season set league records for penalties (163) and penalty yardage (1,358). Allen vowed early on to address the discipline issues, and Kelly said that wasn't lip service. "He harps on it all day long, man," said the ninth-year tackle.

'Neurosurgeon' designs blitz tactics Tarver's youthful appearance, academic background and penchant for concocting new ways to apply pressure to quarterbacks have resulted in players referring to him as a "neurosurgeon" and "baby genius."

When a player's number is dialed up for a blitz, Tarver calls that being "activated." Any member of the defense can be activated, he said, and "when you do have your turn, you need to win. Then you get more turns."

"The defense in the past hasn't been as fun, so to speak," said safety Mike Mitchell. "I feel like you could know what we were in, every down, by the third series of the game.

Whereas now, we've got a lot of – I can't give you guys much, but it's some great stuff." Early returns have been promising. In their first preseason game, the Raiders held Dallas to three points. In their third, they limited Detroit to 281 total yards (65 rushing) and held star wide receiver Calvin Johnson to one seven-yard catch despite his being targeted five times.

The Raiders this season will see four teams that ranked in the top seven in scoring last year – the Saints, Panthers, Falcons and the Chargers twice – but play only one other team (Baltimore) that finished in the top half. Of course, that doesn't include two games against the Broncos, who upgraded at quarterback from Tim Tebow to Peyton Manning.

Tarver said the Raiders have been working through the basics of the defense in camp, and that many of the bells and whistles will be incorporated during the season. The scheme, Tarver said, involves players sticking to "rules" and creating "multiplicity through simplicity," which is a bit of coach-speak that may actually be very appropriate.

For all the changes being promised this season, the essential one is quite simple. The Raiders ranked 27th in the NFL last year in yards allowed per game, and 29th in points allowed, and that needs to get better.

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