Brett Favre retired as quarterback of the Green Bay Packers yesterday, closing the curtain on the career of an athlete who may have been the most beloved ever to play his sport.

Favre’s National Football League records include those for the most passing yards and touchdowns, most consecutive games played, and most games won for a quarterback, in addition to the most Most Valuable Player awards. But what Favre will be remembered for is the sheer joy with which he played football.

“He plays the game like you would if you were in the backyard,” the Packers general manager, Ted Thompson, said yesterday, echoing the comments of countless broadcasters who have described Favre’s approach to the game over the last decade-and-a-half. Few would argue that Favre is the greatest quarterback in NFL history — his propensity for throwing interceptions puts him a step below the best passers of all time — but he was the most entertaining quarterback ever to play the game. No player provided more great memories than Favre. Those memories began in September of 1992, when the 22-year-old Favre replaced the injured Packers starter Don Majkowski and led Green Bay to a come-from-behind victory. He has started every Packers game since then, winning three league MVP awards, re-writing the NFL passing record book, and leading the Packers to victory in Super Bowl XXXI.

But those memories came when Favre was in his 20s, and by the time Favre reached age 30, his skills began to erode; he threw more interceptions and lost some of the zip on his passes. Favre was still a good quarterback, but by the late 1990s, and especially in the early part of this decade, he had ceased to be great. Although Favre still had moments of brilliance (including the legendary 2003 Monday Night Football game when he passed for four touchdowns and 399 yards the day after his father died), his mistakes often outnumbered his highlights. Favre’s decline reached its lowest point in 2005, when he threw a league-high 29 interceptions, and although he was slightly better in 2006, many observers thought he would retire at the end of that year — and, stunningly, many Packers fans thought he should retire. And that made Favre’s renaissance in 2007 all the more amazing. Favre played as well at age 38 as he had in his MVP seasons in his 20s, throwing for 4,155 yards and 28 touchdowns and leading the Packers to a 13–3 record. In December, Favre was chosen as Sports Illustrated’s Sportsman of the Year.

But the season lacked a perfect ending. Favre had an opportunity to lead the Packers to victory in the NFC Championship Game, but instead, Giants cornerback Corey Webster intercepted Favre’s last pass, setting up the field goal that sent the Giants to the Super Bowl and sent Favre into retirement.

That Favre’s retirement was treated as earth-shattering news in the sports world yesterday demonstrates what an effect he had on the hearts and minds of fans, and what an important figure Favre has become in the sports landscape. Favre has come a long way since entering the league in 1991, when he was such an anonymous figure that when the Atlanta Falcons chose him out of Southern Mississippi in the NFL draft, the league executive who announced the pick pronounced his last name, “Favor.” (Seven years later, the correct pronunciation of his name was so well-known that it became a gag in the film “There’s Something About Mary.”)

Almost immediately after the news of Favre’s retirement broke yesterday morning, the question began to surface: Could he change his mind? Given how much Favre loves the game, and how hard a time he had deciding whether to retire in recent years, it seems possible. But when Packers coach Mike McCarthy was asked at his press conference yesterday whether Favre could return, McCarthy said, “not based on the conversations I’ve had with Brett.”

So now the Packers will move on with Aaron Rodgers, the quarterback who became Favre’s heir apparent when Green Bay chose him in the first round of the 2005 NFL draft. Rodgers showed promise when he briefly replaced an injured Favre against the Dallas Cowboys last year, and when the season starts, he will become the first of the nine quarterbacks Green Bay drafted during Favre’s career to start a game for the Packers. (Two quarterbacks Green Bay drafted in the Favre era, Mark Brunell and Matt Hasselbeck, made Pro Bowls with other teams, and two others, Ty Detmer and Aaron Brooks, became starters elsewhere.)

But while Rodgers can succeed Favre, no quarterback could ever hope to replace him. The other great quarterbacks whose careers overlapped with Favre’s — Joe Montana, John Elway, Troy Aikman, Peyton Manning, Tom Brady — all had a businesslike approach to the game. Favre had a childlike approach. That’s why Favre was more fun to watch than any of them.

Mr. Smith is a writer for FootballOutsiders.com.