The Washington Post’s Dave Sheinin followed Redskins quarterback Robert Griffin III from before the 2012 NFL draft to the crippling end of his rookie season for his new book, “RG3: The Promise.”

Robert Griffin III has been in D.C. for only one year, but what a year it was. The Washington Post’s Dave Sheinin followed the 23-year-old Redskins quarterback from before the 2012 NFL draft to the crippling end of his rookie season. Sheinin’s new book, “RG3: The Promise,” shows how a skinny, small-town-Texas kid nicknamed “Ponytail” turned into a Heisman Trophy winner who has the top-selling jersey in NFL history.

What made you decide it was time to do a book, when Griffin had been in D.C. for just one year?

I would say by around October the book came together because by that time you could see the hype was all real. I think it was clear at that point that he was more than just a star football player. This guy was transcendent, a notch above your typical superstar.

What is your favorite anecdote in the book?

I really liked the woman in Waco who had a 1-year-old son named Griffin because they were huge Baylor fans, and she decided out of the blue to invite Robert to her son’s birthday party. Then there’s the party and here comes Robert walking down the street with a few of his Baylor friends, and they stayed for like an hour. It’s just stuff like that where you’re like, this guy is really exceptional.

A lot of the book focuses on the positives of RGIII. If you were to pinpoint one of his biggest flaws, what would it be?

His biggest flaw is also one of his best assets: his hypercompetitiveness. He seems unable to rein himself in. He can’t play as recklessly as he did before. And I’m fascinated to see if he can do that or not — and I think everybody is.

What do you expect to see from Griffin in 2013?

I think he’s going to have a great season. I do think there will be some changes to the offense, but I think that might have happened anyway as a natural evolution, because now you have defenses that have had time to prepare for that zone read and it’s not going to be a surprise anymore.