When an author plans to write a definitive biography on a living subject, the first thing he does, or at least the first thing I usually do, is reach out to the person.

Even if you anticipate a lack of cooperation, it shows a level of humanity, of decency. Plus, once you start calling former teammates, old girlfriends, long-lost teachers and coaches and camp counselors, it allows you to answer the inevitable “Does [FILL IN THE BLANK PERSON] know you’re writing about him?” with a sincere (if not a tad wobbly) “Yes. Yes, he does.”

I note this all to say that, shortly after agreeing to a deal with HarperCollins to chronicle the existence and exploits of Bo Jackson, I sent the iconic two-sport athlete (baseball and football) and Nike pitchman a letter, accompanied by a couple of my past books. “I am asking for your blessing on the project,” I wrote, “as well as the chance to speak with you about your one-of-a-kind life. Which absolutely fascinates me.”

Jackson, pictured here playing for the Tigers, is the only professional athlete in history to be named an All-Star in both baseball and football.

A few days later, a blocked number appeared on my iPhone.

“Mr. Jeff Pearlman?” he asked.

“Yes?”

“This is Bo Jackson.”

We spoke for roughly a half-hour, and he could not have been nicer. Bo was driving to a nearby restaurant in suburban Chicago to fetch his wife a chopped salad, and rambled on about traffic and charity and his blissful low-key retirement since his last Major League appearance, in 1994. He told me that a lot of people aspire to write Bo Jackson books, and—while he had no problem with me doing so—he would not be helping.

Shortly after agreeing to a deal to chronicle the existence and exploits of Bo Jackson, I sent the iconic two-sport athlete a letter. “I am asking for your blessing on the project,” I wrote.

This is a moment endless biographers face, and it always sucks. What to do when the person you’ve devoted yourself to rebuffs your interest?

You hope he changes his mind. (This happened with Davey Johnson when I wrote about the 1986 New York Mets in The Bad Guys Won.) You hope family members empathize with you. (This happened with Green Bay Packers quarterback Brett Favre’s mother and siblings when I wrote Gunslinger.) Or you hope for luck. Which is what happened with Bo Jackson.

One day, not long after licking my rejection wounds, I was chatting with someone from Auburn University (Bo’s alma mater), who noted, casually, “You know, I’m pretty sure Dick Schaap donated his Bo Jackson notes to the school library.”

Jackson accepts the Heisman Trophy, awarded annually to the most outstanding player in college football, 1985.

Schaap, the late sports journalist, had co-authored Bo’s 1990 autobiography, Bo Knows Bo. And, indeed, he had donated his Bo Jackson notes to the Ralph Brown Draughon Library. All of his Bo Jackson notes. Only that wasn’t all. Along with hundreds upon hundreds of pages were hours of recorded interviews, originally preserved on audiocassettes but since converted to digital. Much of the material wound up in Bo Knows Bo—and a lot more of it didn’t.

Suddenly, I went from the notoriously tight-lipped 58-year-old Bo telling me, “Thanks, but no thanks,” to a loquacious, comfortable, 28-year-old Bo spilling the beans on surviving abject poverty in rural Alabama, rightly beating the shit out of a former teammate (Royals third baseman Kevin Seitzer), and, while still a college student, receiving cash and goods from an Auburn booster. (Hey, no one’s perfect.)

The young Bo was funny and chatty and insightful and smart. He loved track, liked baseball, was fine with football. He was impressed with his accomplishments, but not overly so. There were asides aplenty (Bo’s asking his wife for food; Bo’s marveling over one of his young children), which offered a texture otherwise impossible for me to experience. Before long, I felt as if I had sat down with Bo Jackson, as if he and I were collaborators on a book project.

As for Bo, well, I’m not sure what he’ll make of The Last Folk Hero. From my vantage point, I’m his long-lost pal granted access to the most intimate of thoughts. From his vantage point, I’m the guy to tell about a chopped salad.

Jeff Pearlman’s The Last Folk Hero: The Life and Myth of Bo Jackson is out now from Mariner