The burning question on the minds of many is, why take a Raiders offense that last season finished ninth in average yards and per game and 15th in average points per game and install a new blocking scheme and playbook?

To which, Raiders offensive coordinator Greg Knapp said: That’s a “good question; a question worth asking.”

In short, Knapp said, because you teach what you know best, and his system has a track record of working well.

The key is patience. Knapp and defensive coordinator Jason Tarver said their schemes are sound, but they take time to implement and for the players to learn. Bringing back as many players as possible from this year’s team and giving them a year to adjust are going to pay huge dividends.

“I’m a firm believer in the scheme,” Knapp said Thursday. “I’ve been to too many places and had too much experience to know it’s a very productive scheme. Like it is for anywhere you go, when coaching changes occur you want the coaches who are the teachers to teach what they know best. If you do that with the coaches, they’re going to have answers for the issues that come up in the system.”

Knapp said his history in retooling offenses shows that players need a year or so to get acclimated but, once they’re up to speed, good things happen.

“Every place I’ve been to, it’s usually going to take at least a year’s transition time to get everything taught … ,” Knapp said. “If you take a business structure and you make those changes, it’s going to take a year’s time to process everything and learn it. Once they master it, you can add to it. Right now, it’s taking some time.”

When posed the same question, why change the offense? Raiders coach Dennis Allen said he, too, is a firm believer in what Knapp is doing.

“There’s been a lot of change, and when there is a lot of change, sometimes you don’t get the results that you’re looking for right away,” Allen said. “But when you believe in something, and you stick to it and you know it’s the right plan, it ends up working out.”

Next season is when the Raiders can expect those results, Knapp said. And how is that going to manifest itself?

“More consistency and higher scoring points,” Knapp said, “because we’re not able to keep those drives long enough right now to get the points on the board. So, by keeping the system in place and keeping the bulk of the players here, now we keep the drives alive and we get our point total up into the mid-20s, and that’s what we want to be.

“If you’re in the mid-20s to high 20s, you’re going to be in the top 10 of the league in scoring, and that’s ultimately what has to happen. To get 11 guys on the same page, you need some reps and experience together and with a year’s offeseason work of that and a better offseason system, the performance level usually goes up the next season.”

In Knapp’s second season as offensive coordinator in three previous stops, his team’s scoring dropped by an average of 1.1 points per game and an average of 4.5 yards per game in Year 2.

Tarver said, “I want it now,” when asked about the time it takes to get a scheme at peak performance. “It’s a now business.”

At the same time, he said, the players are getting better as the season progresses, which is an encouraging sign that they are grasping the scheme.

“With the change of personnel, now they’re realizing what the scheme can do for them,” Tarver said. “It’s been good. With a year under our belts and keeping as many of these guys as we can, it’ll grow big time.”

Cornerback Michael Huff boasted of the Raiders having a top-five defense this season. He now says that the defense has a “long way to go” before it’s where it needs to be.

Bringing back as many players as possible is paramount.

“You want to keep a lot of the same guys there, especially in the secondary because it’s all really communication, talking and making sure everybody is on the same page,” Huff said.

Veteran defensive end Andre Carter said he understands how people might question the merit of bringing back the same scheme and many of the same players, given the lack of success this season.

However, he said he, too, has seen the value of continuity during the course of his long NFL career.

“I’ve had eight defensive coordinators in my career,” Carter said. “Learning the scheme takes a lot of time. The first year, yeah it’s tough. It’s all growing pains and you learn as you go. Coming into that second year, the comfort level is a little bit better, the communication is a little better and the execution is so different.

“This year is just a level for the growth and development of the younger guys, as well as the vets trying to adapt the new scheme and philosophy.”

— Middle linebacker Rolando McClain declined an interview request after practice.

McClain said, “Coach covered everything you could ask me. I ain’t got nothing to say about anything,” when asked if he wanted to speak with the media.

McClain, of course, was referencing Allen saying he and McClain had a talk Wednesday, at which time Allen outlined for McClain what he expected from him the rest of this season and beyond.

McClain was suspended for two games by the Raiders for conduct detrimental to the team. He returned from his suspension Monday as the Raiders backup middle linebacker and special teams player.

— Allen said defensive tackle Richard Seymour suffered a “setback” in his return from a hamstring injury.

Seymour missed the past five games as a result of the injury. He practiced Monday for the first time since he suffered the injury Nov. 4.

“We’ll evaluate him as we finish out the week, but I thought he practiced well yesterday and then early today,” Allen said. “It kind of grabbed him a little bit, so we’ll see.”

— Strong safety Tyvon Branch missed practice today for the third straight day this week. However, there is hope that he might be able to rebound in time to play Sunday against the Kansas City Chiefs.

“He was on the side working out with the trainers,” Allen said. “I’m hopeful that we’ll be able to get him out here and practice a little bit tomorrow. His mind-set is he wants to play this weekend.”

— The Raiders received an extension from the league in hopes of selling enough tickets by day’s end Friday to avoid the Chiefs game being blacked out.

The Raiders need to sell at least 85 percent of the tickets for the game to be televised locally. Typically, when the Raiders ask for an extension, the game winds up being televised.

Six of Oakland’s first seven regular-season home games this season were televised locally. The Browns game is the only one that was blacked out.

— Allen and general manager Reggie McKenzie said they want to get a good look at young players such as quarterback Terrelle Pryor, offensive lineman Tony Bergstrom and defensive linemen Christo Bilukidi and Jack Crawford the final three games.

That remains the plan, Allen said, just don’t expect any of those guys to start.

“I don’t see any real major changeups as far as the starting lineup’s concerned, but we do want to see some of these guys get in some game action,” Allen said. “And how much that is, I don’t know exactly right now. A lot of that, the game will dictate what that is.”

— Young players that don’t figure to get much playing time the rest of the way are tight ends Richard Gordon and David Ausberry.

From the sound of it, they don’t factor much into the Raiders long-term plans, either.

“We’ve had a chance to look at these guys a little bit,” Allen said, “and we kind of know what we’ve got in these guys. They’re still in the lineup and they’ll still be used pretty much the same way we’ve used them.”

That means a handful of offensive snaps and the rest on special teams. Not exactly a ringing endorsement of either player moving forward.

— Looks as if it’s full systems go for running back Darren McFadden, who is doing much better in his return from an aggravated ankle injury than many might have expected.

How’s Darren looked all week?

“Darren’s been great,” Allen said. “He’s been great all week. I haven’t noticed anything where he’s had any issues at all. So, I’m really kind of expecting him to be full go.”