Brett Favre, by his own admission, will never be mistaken as the NFL's Norman Einstein. He reiterated this point recently, explaining that he was a couple of years into his gig as the Packers' starting quarterback until he finally mustered the courage to ask backup Ty Detmer what coach Mike Holmgren meant when he kept talking about "nickel defenses."

"Finally, I said, 'I just gotta know.' So I said, 'Ty, I gotta ask you a question.' And Ty was about as goofy as I was.

"He says, 'What's that?'

"I said, 'What's a nickel defense?'

"He gets real quiet. He says, 'Are you serious?'

"'Yeah, I'm serious.'

"He says, 'Well, they basically take out a linebacker and bring in a DB.'

"I said, 'That's it?'

"He said, 'That's it.'

"I said, 'Who gives a s--t?'"

If it all sounds too ridiculous to be true -- how can an NFL quarterback not know about nickel defenses? -- it's not. Detmer has confirmed as much.

"He didn't know," Detmer told TheBigLead.com's Tully Corcoran. "He was sincere in asking."

Detmer continued: "[I]t was during a serious part of the meeting. This wasn't jacking around in the locker room, and throwing it out there. I did kinda question it, you know, 'Are you serious?' You could tell he was, I just figured I'd better double-check it."

Detmer's account meshes with what he told CBSSports.com's Nate Peterson in December 2015 about what it was like playing with Favre in Green Bay.

"One of our first blitz meetings, we would go in early Wednesday morning and the QBs would meet with the O-line coach, the RBs coach and the QB coach and go over teams' blitzes for that week and what our adjustments were," Detmer said, via Peterson. "The O-line coach would be on the board, he'd say, 'In the nickel, they like this blitz.' Brett kinda leaned over to me and says, 'What does nickel mean?'"

In that same vein, Detmer tells Corcoran that Favre's mastery of the playbook was ... well, lacking.

"It was the first time I'd been around anybody that just kind of winged it," Detmer explained. "You could tell the first year he got to play, first year in Green Bay, Don Majkowski was the starter and [Favre] goes in, and he wasn't great at remembering the formations. Back then we didn't have the coach-and-quarterback helmet. We had to memorize all the formations, and we would signal in the play. You had to know the formation for that play that week, and they changed it every week. You knew he didn't really have a great grasp on the formations and didn't really study them as hard as they needed to be studied to be able to call them every week. He was a genuine guy that loved playing the game, but didn't really put a ton of time into it."

Again, this squares with what Detmer told Peterson: "He couldn't put a formation with the play together that first year. You never knew what formation was going to be called. I remember Sterling Sharpe was one of our veteran receivers and he would come off the field laughing. He was like, 'You should've heard what he called that time.'"

Once again, Favre is the exception to the rule; when you hear a quarterback "is struggling to pick up the offense," that typically means he'll be on the bench until the issue is rectified. All Favre did was parlay his freewheelin' style into a 20-year career that included 24 postseason appearances and a Lombardi Trophy.