From 1962 through 1965, the Bulls defense ranked among the national leaders, posting 12 shutouts in that span as well as producing Gerry Philbin.

[10] During his time with the Vikings, he started working on a defensive nickel scheme designed to disrupt the passing game.

[11] This was due in large part to Mike Singletary's ability to single-handedly dominate the middle of the field.

[22] The Bears defense set several NFL records in 1985, and led the league in turnovers forced and surrendered the fewest yards, points, and first downs.

[24] Ryan released running back Earnest Jackson, who had rushed for more than 1,000 yards in both of the previous two seasons,[25] and limited the playing time of veteran quarterback Ron Jaworski.

Ryan coached players such as Randall Cunningham, Reggie White, and Andre Waters and drafted Pro Bowlers Seth Joyner, Clyde Simmons, Jerome Brown, Eric Allen, Cris Carter, Fred Barnett, and Keith Jackson.

[26] On October 25, 1987, he came under fire after a game against the Dallas Cowboys by scoring a touchdown in the final seconds, when the outcome was no longer in doubt.

[28] The controversy marred a season in which the Eagles improved to 7–8, which included a 31–27 win over the eventual Super Bowl champion Redskins at Veterans Stadium.

On November 22, 1989, Ryan found himself at the center of another scandal, when Cowboys head coach Jimmy Johnson alleged Ryan had taken out a "bounty" on two Cowboys players—then-current Dallas (and former Philadelphia) placekicker Luis Zendejas and quarterback Troy Aikman in a game dubbed "Bounty Bowl" played on Thanksgiving Day at Texas Stadium.

On January 8, 1991, Ryan was fired by the Eagles after going 43–35–1 in five seasons, a total that included an 0–3 record in playoff games.

"[35] Ryan thought that last-minute defensive stands lost him two players to injuries when the offense could have simply run the clock out.

When they were at arm's length, "Ryan ... attempted to punch Gilbride in the jaw"[35] before linebacker Keith McCants and several other Oilers players separated them.

[37] The Oilers lost to the Kansas City Chiefs 28–20 in a divisional round match at the Astrodome two weeks later on January 16.

After scoring the Chiefs' first touchdown on a 7-yard pass from Joe Montana, Keith Cash fired the football at an image of Ryan's face on a banner hanging beyond the end zone.

"[38] After being given a large share of the credit for the success in Houston in 1993, Ryan was named head coach and general manager of the Arizona Cardinals in 1994.

"[40] Ryan was cited as providing a spark of interest in the team with his outspoken nature; he also named his two sons in Rob and Rex to be assistant coaches.

After a miserable 37–13 loss on Monday Night Football to the Dallas Cowboys to close the year out, Ryan (who mistakenly left the field before the final seconds) was fired by owner Bill Bidwill on December 26.

[44] Ryan was an assistant on three different teams to make the Super Bowl (New York Jets, Chicago Bears, and Minnesota Vikings).