The Green Bay Packers created a McVay coaching tree, of sorts, by hiring his former offensive coordinator, Matt LaFleur, who is 39, to be their head coach. The Cleveland Browns hired Freddie Kitchens, a 44-year-old offensive guru, to lead their staff. And in an extreme example of McVay mania, the Arizona Cardinals’ website, in its official announcement about the hiring of the 39-year-old Kliff Kingsbury as the team’s new head coach, noted that Kingsbury was friends with McVay.

That the two had never coached together seemed not to matter, though after some blowback, the team amended the announcement to remove the part about their friendship while still noting that McVay is a young “offensive genius who has become the blueprint of many of the new coaching hires around the N.F.L.” and had recently offered Kingsbury a chance to join the Rams as an offensive consultant.

“It’s certainly humbling and flattering,” McVay said of the hiring trend, “but I think more than anything it’s a reflection of the success the Rams have had.”

In the end, teams may discover that replicating McVay will be difficult.

Young, offensive-minded coaches are “the vogue thing right now,” said Brian Billick, the former Baltimore Ravens coach. “Some will be successful, and some won’t. Eighty percent will probably fail.”

Very few coaches have engineered the kind of turnaround that the Rams have made in two seasons under McVay, who, despite having coached in the N.F.L. since 2008, is younger than one of his players, and two of the Patriots.