Washington Coach Chris Petersen holds the Apple Cup trophy after beating Washington State last month. (Ted S. Warren/AP)

Every so often, Josh Weinstock exhumes the handwritten letter his wide receivers coach at California Davis sent him 26 years ago, three pages long and curled at the corners. He has not spoken with Chris Petersen in years. But Weinstock still reads Petersen’s words because they changed his life. “I think about him all the time,” Weinstock said.

Weinstock runs an online food supplies company and raises young kids, and Petersen coaches the University of Washington, which in the course of three years he has pulled from mediocrity to the College Football Playoff. When the No. 4 Huskies face No. 1 Alabama in Atlanta on New Year’s Eve, it will punctuate the revival of a proud program and mark a new apex for a coach whose journey began in the mid-1980s at Division II UC Davis, a mostly unknown sliver of football history.

Petersen has become one of the best coaches of his era, a West Coast answer to Nick Saban and Urban Meyer. For 13 years as Boise State’s offensive coordinator and its head coach, he helped turn the Broncos from a blue-turfed curiosity into a perennial national player. At Washington, he runs a program with all the trappings of a powerhouse. Beneath the surface, Petersen has built teams upon the values he learned under a legendary coach at UC Davis, a school that viewed itself in the mid-80s as an Ivy of the West.

“It’s the foundation and basis of probably everything we do around here,” Petersen said.

In San Francisco, Weinstock will watch Washington and the coach he met as an 18-year-old. He played on the first team Petersen coached, the 1987 freshman squad at UC Davis. They moved up together, as a wideout and a wide receivers coach at Davis. After Weinstock missed his sophomore season, Petersen sent him a note.

Petersen talks to player Dante Pettis during the Pac-12 Championship game. (Robert Reiners/Getty Images)

“I’m writing this letter as your coach, not your friend,” it began.

Not your typical coach

The man who shaped Chris Petersen weighed 140 pounds and stood 5 feet 8 inches. Jim Sochor drew from the teachings of Bill Walsh, Laozi and Ralph Waldo Emerson. He recruited players to UC Davis without scholarships and held no spring practices. When class conflicted with practice, he told players to attend class. Sochor mistrusted rules and instituted only one, meant to promote discipline and self-respect: A player’s helmet could not touch the ground when he was not wearing it.

“That one rule carried over into everything,” Weinstock said. “If you couldn’t do that, you couldn’t do a lot of stuff. If you don’t respect the school, you probably don’t respect the opponents or yourself. That one rule summed all that up for us.”

“He was not your typical football coach,” Petersen said. “He was like a chemistry professor. First time I met him, I was like, Huh? This is the coach?”

Sochor had the good fortune of coaching Walsh’s son, Craig, which led to meetings at the San Francisco 49ers’ training camp. Sochor became one of the earliest adopters of Walsh’s West Coast offense. They grew close enough to share notes.

Starting in Sochor’s second season, 1971, the Aggies won 18 consecutive conference titles with players who would become doctors and chemists, lawyers and businessmen. He encouraged a life outside of football and carried a single-digit handicap on the golf course. He declined chances to coach at larger schools in part because he cherished teaching physical education at Davis.

“Jim had an overall philosophy about developing a whole person,” said Bob Biggs, who served as Sochor’s offensive coordinator and would go on to coach Davis for 20 seasons. “But when it came to football, we were serious about it. Everybody who left Davis, they left Davis with that balance-of-life aspect and applied it in whatever philosophy of the program they have now.”

Davis became a coaching incubator, a charmed pocket of football intellect. Coaches rolled out of Davis and spread across the landscape. Paul Hackett, who became an assistant on Walsh’s staff. Mike Bellotti, who would jump-start Oregon and spawn Chip Kelly. Dan Hawkins, who would bring Petersen to Boise State. Gary Patterson, who would usher TCU to prominence.

Petersen entered Sochor’s world in 1985 as a junior college transfer quarterback. What he lacked in arm strength he compensated for with accuracy, smarts and athleticism, an ideal fit for Sochor’s system. As a senior, Petersen — everyone called him “Petey” at Davis — set a school record for completion percentage that still stands.

His first game, coincidentally, came at Boise State. As Petersen walked on to the field, Sochor saw his bulging eyes and said, “Calm down.” Petersen overflowed with competitiveness, the guy who would talk trash during intramurals. Sochor wanted to win, too, but he expressed it in understated ways.

“He was different from me, in so many ways,” Petersen said. “That’s when people can teach you so much. That was the beauty of me being around him.”

When Petersen’s playing career ended, he entered a Master’s program in educational psychology. He had no interest in coaching. His father, Ron, coached a junior college team in his home town of Yuba City, Calif. “I felt like I cared more about winning and losing than half the team did, and I wasn’t on the team,” Petersen said. “I was like, I’m not doing this.”

But when Sochor asked him to coach the freshman team, an assignment most coaches had to wait years for, Petersen accepted. He stood in front of his first team at 23, surrounded by players only four or five years younger.

“His demeanor was beyond his age,” said Alex Gash, an offensive tackle and captain on the freshman team. “He’s definitely not a yeller. He’s a lot more cerebral. Sochor was that way. Chris took a lot of the best things Jim had.”

His players may have respected him, but Petersen was hiding insecurity. “I couldn’t even get our guys in stretch lines after two weeks,” Petersen said. “It was like herding cats. I had no clue what I was doing.”

The challenge was what made him like it. He realized he wanted to coach.

Needing a new challenge

As Petersen moved up the coaching ranks, he thought he could spend the rest of his life in every new job. He realizes now it came from Sochor, who told his coaches, “Don’t worry about your next job. Worry about this job, and make this place the best it can be.”

Bellotti brought Petersen from Davis to Oregon as a wide receivers coach, and they became close friends. Years later, as an athletic director, Bellotti wanted to interview Petersen for the head coaching job at Oregon when Petersen was still at Boise. “Why would I want to do that?” Petersen replied.

“I feel comfortable in saying this — he was offered a lot of big jobs,” Biggs said. “Some might say bigger than Washington.”

As conferences realigned, Boise flirted with the American Athletic Conference, which would have created far-flung trips without making it likely Boise could gain entry into the national title discussion.

“He thought maybe he’d run his course at Boise,” Bellotti said. “The thought probably started to hit him, ‘Do I need one more challenge to take on?’ ”

After the 2013 season, Washington offered Petersen its head coaching job. He had rebuffed Southern Cal and Tennessee and many others. He felt challenged maintaining success at Boise, but after eight years as the head coach, it had begun to feel the same.

“I felt in my heart, this is time,” Petersen said. “I need some more growth. And to really be challenged. That’s what happened. You come here, and it’s completely different. Extremely challenging. And hard. And frustrating.”

Washington went 8-6 in his first season and 7-6 his second year before the Huskies exploded this season. Petersen, 52, has never eyed his next step before and ended up leaving, he admits. But he believes Washington will be his final job.

“There’s not another place or job out there where I’m like, ‘Well, if that opens . . . ’ ” Petersen said. “I don’t even kind of think like that.”

On the surface, the difference between Davis and the program Petersen runs could not be starker. He has a laundry list of rules. Players meet constantly, about nutrition and navigating social media and a thousand other things. There is no freshman team. Class schedules do not interfere with practice. Petersen wishes he was better at balancing his life with football.

At the core, the Davis influence still runs deep. Sochor died of cancer last year at 77. At the memorial, Biggs spoke about the beauty of a Davis practice: 150 kids between JV and varsity, all there because they wanted to be, veterans making sure freshmen knew not to let helmets hit the ground. If Sochor were around today, he would see something different at Washington, yet the same.

“He’d probably tell me to relax and enjoy this more than you are,” Petersen said. “I think he would like our team. I think he would like how we interact with our players, how we coach them.

“He was just such a philosopher of life. I think a lot of that is translated, really unknowing, to me over the years. Like, this is what we do with our players. These guys hear this message over and over, and we work on them. I know it’s like, ‘Really? I got to hear this again?’ But I know that that’s going to matter to them.”

Weinstock could tell them. After he read Petersen’s letter, he decided he was lazy. He devoted himself, became Davis’s MVP and a captain and spent three weeks in the Kansas City Chiefs’ training camp. “Chris was right,” Weinstock said, laughing. “I was not genetically gifted enough to hang around with the Kansas City Chiefs.” But he applied the lesson of how far constant work could take him.

“This is what stays with me about life,” Weinstock said. “Not just football. It feels good that somebody would care about you this much.”

On Saturday, Weinstock will root for his old coach, and if he looks at the sideline, he will notice a subtle and familiar detail. When Chris Petersen’s players remove their helmets, they are not allowed to let them touch the ground.