“When we pitched it out and I was running with the ball,” Reeves told NFL Films, “I noticed both the safety and corner coming up, which meant that Rentzel would be open.” He added, “When I threw it I thought I had a chance to overthrow it, but the wind was in our face and thank goodness it held it up.”

The Packers came back to win, 21-17.

In 1970, Landry made Reeves a backfield coach. He was still an active player at the time.

“You think you’re pretty smart after a few years in the league as a player,” Reeves told The Associated Press before the 1970 season. “But you get into the coaching end and you realize how much work is involved in learning the game.”

After coaching the Broncos and the Giants, Reeves took over the Falcons in 1997. Following a 7-9 first season, he quickly turned Atlanta into one of the best teams in the N.F.L. The team finished the following year with a 14-2 record; its star running back, Jamal Anderson, gained 1,846 yards.

But as the Falcons were en route to their 12th victory, against the Saints in New Orleans in mid-December, Reeves felt a burning sensation in his chest and throat; a day later, he underwent quadruple bypass surgery.

He missed the Falcons’ two final regular-season games, but he returned for a playoff run that led to the team’s appearance in the Super Bowl against the Broncos, a matchup between Reeves and Shanahan. The Broncos won, 34-19.

Reeves was named A.P. coach of the year for a second time.

But the Falcons were not the same in the ensuing years. Anderson tore up his knee early the next season. They had losing records in four of the next five seasons. With the team a dismal 3-10 in 2003, Reeves was fired with three games left in the season.