To reach Stanford’s football weight room, one must navigate a pair of nondescript hallways and descend a set of stairs into the basement.

Sports performance director Shannon Turley’s office is tucked away to the right side of the large space.

Inside Turley's office, a full wall is occupied with massive, four-inch binders, labeled by player name, each containing blow-by-blow details of their training regimens in painstaking detail. The room is essentially a complete archive of every repetition of work that the Cardinal have invested since the beginning of 2007, when Turley arrived as part of Jim Harbaugh’s staff.

On the right side of the wall are the names of past Cardinal players, including Andrew Luck, Toby Gerhart, Richard Sherman and Trent Murphy. On the left side are current Cardinal players.

Christian McCaffrey amassed 368 yards in the 2016 Rose Bowl. AP Photo/Lenny Ignelzi

The organizational strategy is simple: When a current Stanford player sets a goal, Turley can retrieve the binder of a former player to show him a blueprint for NFL success. (Recently drafted lineman Joshua Garnett, for example, told coaches upon his arrival four years ago that he wanted to become the Cardinal’s “next David DeCastro”).

Every Stanford player can consult the binder of a certain NFL alumnus as an effective reference point.

Well, every Stanford player, except one. Because Christian McCaffrey has become an exception, both in his record-breaking on-field performances and in the off-field work that supports them.

“Christian is authoring his own binder,” Turley said. “He’s carving his own path. He’s unlike anybody we’ve ever had.”

Technically, McCaffrey is unlike anybody that any college football team has ever had: Never before in the sport’s history has a player amassed 3,864 all-purpose yards in a single season. And while record-breakers normally graduate or move on to the NFL draft, McCaffrey did that damage as a sophomore, so Stanford is enjoying the unique prospect of trying to improve upon last season's production.

Even Stanford coach David Shaw didn't anticipate McCaffrey's progression as a sophomore. "The year he had last year," Shaw said. "I anticipated that would be his junior year."

Stanford coaches backed away from McCaffrey’s planned training regimen earlier this offseason to allow his body to recover from the 437-touch workload he endured last year.

“He didn’t do a lot of the traditional lifts,” Turley said. “I wanted to focus more on rebuilding him from the ground up because of all the things he went through physically.”

McCaffrey is back to full-go now. His body fat is down about four percent, and his measurements -- Turley conducts a battery of tests, including a laser-time flying 20-yard dash -- have improved.

“He’s substantially better than he was during his exact training period last year,” Turley said. “So despite all the runs, catches, punt returns, and kick returns, this guy is at a higher physical level than he was last year. You’re talking about a guy who’s leaner, faster, stronger, and more explosive now.”

Nowhere is that more evident than on the practice field at 6 a.m., where Turley conducts brutal workouts that are centered on engaging players in cutthroat competition.

“We’re trying to put kids into fight-or-flight situations to see what they’re made of,” he said.

After losing the combined obstacle course to a teammate last season, coaches say McCaffrey is demanding extra feedback and critique this offseason.

"He's working on being the best well-rounded football player in America because that's what he's got the ability to be," Shaw said. "He's always been that way. His body's continued to mature. When you see him, he's a little bit bigger, and it's not that we're doing anything different. He's 19 going on 20. His body's still maturing, his body's still growing."

The Cardinal now struggle to find a worthy opponent for McCaffrey in the "10-yard fight," in which two players are attached to each other by belt and chest harness. They run in opposite directions with the goal of dragging the other against his will for five yards.

“This is the drill where he is going to break your spirit,” Turley said. “He knows it’s an opportunity to break you.”

Each round of the 10-yard fight lasts one minute, so a player can drag his opponents the five yards more than once -- provided that they both line up in time to go at it again. But the battle is so physically taxing that players rarely want to line up for another drag, even if time remains on the clock. Normally, coaches must prod the exhausted participants back into a ready position so that they can do more dragging.

But here, once again, McCaffrey proves to be cut from a different cloth.

“Now, Christian is doing the coach's work,” Turley said. “He’ll say, ‘Coach, we’re ready.’ And he’ll push his opponent into that ready position, because he just wants to go kick your ass again.”