Jason Tarver recalls meeting with 49ers general manager Bill Walsh, coach Steve Mariucci and front office executive Bill McPherson in 2001, hoping to get a job as a low-level assistant coach.

His résumé included a master's degree in biochemistry and molecular biology and an award bestowed by the UCLA chemistry department for distinguished teaching in biochemistry.

All which of made Walsh wonder why Tarver was sitting at the table.

"The first thing he asked me was, 'Why don't you go out and invent something?' " Tarver said.

A dozen years later, Tarver, in his second season as defensive coordinator, has helped reinvent the way the Raiders play defense.

Quarterbacks Philip Rivers of San Diego and Alex Smith of Kansas City came out of games against the Raiders talking about the confusing array of blitzes and alignments thrown their way.

Long a four-man rush team with press coverage influenced by the late Al Davis, the Raiders under Tarver and coach Dennis Allen are mixing coverages, blitzing often and seldom showing the same thing twice.

There are 10 new starters, none of whom were big-ticket items in the offseason but have the shared trait of being enthusiastic workers who believe in team defense.

Of the 16 sacks generated by the Raiders, Lamarr Houston has the most at three, and the remaining 13 are divided among 11 players.

Opponents are averaging 22 points per game and 99.0 yards per game rushing, with only the Denver Broncos and Peyton Manning putting up the kind of points (37) and yardage (536) the Raiders have given up far too often in the last 10 years.

The Raiders are faster, are better tacklers and playing smarter than at any time in recent memory, and Allen credits Tarver with allowing his unit to play as fast as possible.

"He's really smart, and he's able to take something that might seem complicated and make it as simple as he can for the players," Allen said.

Free safety Charles Woodson, aware of Tarver's advanced education, has a mental picture of his coach in the role of a scientist.

"A lab coat, glasses, pens in his pocket," Woodson said. "I can see the whole thing."

Tarver, 39, who chose coaching over medical school, doesn't see his career path as unusual. Chemistry, like coaching, is about applying rules and logic to solve problems.

"You don't know how that weird-shaped brown ball and 22 pieces are going to move," Tarver said. "It's the ultimate puzzle -- a human puzzle."

In truth, for as good as Tarver was in his studies at Pleasanton's Foothill High, Santa Clara University and graduate school at UCLA, his passion was always football.

A safety at Foothill for coach Matt Sweeney, Tarver immediately took to scouting and preparation, which made up for what he lacked in pure athletic ability.

"He was just so off-the-charts smart," Sweeney said. "He was a 17-year-old that really could have been hanging out with 40-year-olds. Sometimes you win because of a certain number of guys who are behind the scenes acting like a coach with his classmates. That was Jason."

As a senior, Tarver blew out his anterior cruciate ligament, and according to Sweeney, "played his whole senior year without an ACL. He just put on a brace and lived with it."

Still living with it, as it turns out. Tarver had arthroscopic knee surgery last Thursday and was back in the office watching film by midafternoon.

Tarver's father is a research chemist at Lawrence Livermore Laboratory, while his mother, sister and brother are all educators.

"We didn't talk about if we were going to college," Tarver said. "It was about where and when you would go to college."

Jon Evans, a Foothill teacher and assistant football coach who was a close friend of Tarver's brother James, spent much of his youth at the Tarver home. On the court where they lived, pickup football and basketball games were daily occurrences, with Jason doing most of the organizing.

Although Tarver was an "A" student, Evans can't remember a time when he saw him doing homework.

"He was always working on football and studying Coach Sweeney's game plans," Evans said. "I don't think he had to spend a lot of time to get straight A's. I don't think he was challenged academically until he got to college."

Tarver was a biochemistry major at Santa Clara but played football at West Valley College in Saratoga after Santa Clara dropped football. He worked for a year as an assistant coach at West Valley and caught the coaching bug, which he took with him to UCLA -- where Tarver worked as a graduate assistant coach and eventually as an instructor while getting his master's degree.

"I would finish with spring ball, throw a lab coat over my football coaching stuff and literally run across campus to teach a four-hour lab, and I loved it," Tarver said.

Raiders running backs coach Kelly Skipper, then the offensive coordinator at UCLA, said Tarver was immediately identified as an "out of the box thinker" who absorbed everything he could on both sides of the ball. The coaching staff was both amazed and amused at Tarver's workload and surprised that he seemed like a fairly normal person.

"The thing about him is here's a guy with that kind of intellect, and he relates to people so well," Skipper said. "He's not off in his own little world. I think that's what makes him a pretty good coach, because he can talk to players. He can talk to anyone, at any level."

When Tarver interviewed with the 49ers to be a quality control assistant, he talked for 3½ hours with Walsh, Mariucci and McPherson, got the job, and remained on the 49ers staff through the tenures of Mariucci, Dennis Erickson, Mike Nolan and Mike Singletary, coaching both offense and defense.

Tarver was hired by David Shaw to be co-defensive coordinator at Stanford before moving on to the Raiders last season.

His coaching style is best described as relentlessly positive, and players appreciate the freedom to make their own adjustments within the system.

"He doesn't coach any robots," cornerback Tracy Porter said. "He calls the play, and if you see something different and make the play, he's all for it."

Said linebacker Sio Moore: "He allows you to just go, and gives everybody the confidence to make a play. Once you understand a piece of his brain, what he's trying to do, it makes things less complex. It makes it easy."

Sunday's game
Pittsburgh (2-4) at Raiders (2-4), 1:05 p.m. CBS

THE TARVER FILE
Name: Jason Tarver
Job: Raiders defensive coordinator
Age: 39
Bay Area stops: Foothill High (Pleasanton), Santa Clara University, West Valley College, 49ers, Stanford, Raiders.
Advanced degrees: Masters of biochemistry and molecular biology from UCLA.
Quotable: "He was just so off-the-charts smart,'' Foothill High coach Matt Sweeney said. ``He was a 17-year-old that really could have been hanging out with 40-year-olds. Sometimes you win because of a certain number of guys who are behind the scenes acting like a coach with his classmates. That was Jason.'

THE TARVER FILE
Name: Jason Tarver
Job: Raiders defensive coordinator
Age: 39
Bay Area stops: Foothill High (Pleasanton), Santa Clara University, West Valley College, 49ers, Stanford, Raiders.
Advanced degrees: Master's of biochemistry and molecular biology from UCLA.
Quotable: "He was just so off-the-charts smart," Foothill High coach Matt Sweeney said. "He was a 17-year-old that really could have been hanging out with 40-year-olds. Sometimes you win because of a certain number of guys who are behind the scenes acting like a coach with his classmates. That was Jason."