CHANDLER, Ariz. – You have to turn all the way to page 50 of the New England Patriots media guide before you come across the mysterious man many people believe is the secret to the team’s success.

The man has big, horn-rimmed glasses, a graying mustache and a tuft of slightly mussed hair on his head.

“Ernie Adams, Football Research Director,” it reads.

Adams has been with Patriots coach Bill Belichick since he took the Patriots job in 2000 after previously working with him with the Giants and Browns. The two went to prep school together, and those around the Patriots describe a never-ending dialogue between the two. He is believed to be the primary voice in Belichick’s headset on game day and is a constant presence at Patriots practice.

But even members of the Patriots are not quite sure what Adams actually does. Nor they are not willing to say.

“Nothing,” offensive line coach Dave DeGuglielmo says when asked what he could say about Adams’ role. “He does a lot, but I can’t tell you anything.”

Here’s how important the 61-year-old former Wall Street trader is to the Patriots: In the team’s Arizona hotel, two members of the Patriots’ staff have offices with doors on them. One is Belichick. The other is Adams.

“I really don’t know what he does,” wide receiver Danny Amendola said. “I’ve gotten to talk to him just a little bit. I feel like deep down he might be the mad scientist behind all of this. I’d like to know.”

In the media guide, Adams’ job description is: “researching special assignments for both the coaching staff and the personnel department.”

People who have worked with Adams describe him as a master of the NFL rulebook and a football historian.

“I don’t know everything he does,” offensive lineman Dan Connolly said. “I know that whenever I’ve had a question come up about rules, I’ll go to him. He always seems to know the answer.”

Patriots special teams coach Scott O’Brien said Adams helps him with any rules changes and they sometimes discuss strategy. Asked why Adams shies away from any recognition or attention, he said,

“You’d have to ask Ernie.”

Good luck with that.

The Patriots did hundreds of interviews this week, from owner Robert Kraft down to the last man on the roster and all of the position coaches. Not Adams. He rarely does interviews, preferring to keep out of the spotlight. Since he is not technically a coach, he is not required to do any interviews, even during Super Bowl week.

“He is the black ops of pro football analysis,” DeGuglielmo said. “He is undercover and out of sight.”

One of the few interviews Adams has done was in 2008 with the alumni magazine of Northwestern University, where he went.

“The truth is, I’ve always preferred to fly under the radar,” he said in the article. “I just don’t need a lot of notice. I love what I do, and that’s enough. And there’s a lot of stuff about being in the spotlight that I just don’t want. Let someone else worry about the media and the second-guessing and all the pressure.”

Adams grew up in Massachusetts and became obsessed with football, reading Vince Lombardi’s “Run to Daylight” multiple times and “Football Scouting Methods,” by a Navy assistant coach named Steve Belichick. During his senior year at Phillips Andover Academy, he met Bill Belichick, who had just entered the school. He found out Belichick was Steve’s son and a friendship was born.

After attending Northwestern, Adams got a job with the Patriots in 1975. He went to the Giants in 1979 where he was reunited with Belichick. He spent the first three years as an assistant coach, mentoring a young Phil Simms, and the last three in the scouting department. He left to work on Wall Street before the Giants went to the Super Bowl in 1986. Adams returned to football in 1991, when Belichick became the head coach of the Browns, left again after Belichick was fired then rejoined Belichick in New England in 2000. The two have been together ever since.

In the book “The Education of a Coach,” author David Halberstam describes Adams as “Belichick’s Belichick.”

When Belichick shows a new strategy like playing with eligible and ineligible receivers to confuse the defense during the playoffs, many believe Adams is behind it. He also gets the finger pointed at him when the Patriots stray from the rules. All those taped signals from the “Spygate” controversy? Belichick admitted they were going to Adams for analysis.

But no one is quite sure exactly what Adams really does, it seems, outside of Adams and Belichick. In Cleveland, Browns owner Art Modell once said, “I’ll pay anyone here $10,000 if they can tell me what Ernie Adams does.”

In Halberstam’s book he describes a team meeting where a photo of Adams was shown on the big screen and underneath was written, “What does this man do?”

Adams told the Northwestern alumni magazine he lists his profession as “research” on his tax return.

“He does anything and everything that Bill asks him to do,” tight ends coach Brian Daboll said.

What exactly that is, no one will say.

“His insight is vast,” DeGuglielmo said. “He goes back years and years in his research. Exactly what he does, I’m not at liberty to say.”