Scan a list of the NFL’s best quarterbacks nowadays, and you’ll find names such as Russell Wilson, Cam Newton, Tyrod Taylor and even that of rookie sensation Dak Prescott — dynamic passers who can run the ball, too. The question of whether a team can succeed with that kind of dual threat under center has basically been settled in today’s game; such a QB has led his team to the Super Bowl in each of the past four seasons. And no five-year period in modern NFL history has seen quarterbacks gain more rushing yards per game than they have over the past five seasons. The golden age for mobile passers is right now.

In the not-too-distant past, a quarterback was supposed to stay in the pocket, survey the field and make the throw — not take off and run. Not only was rushing mostly absent from the job description, it was often seen as a bad habit that needed to be discouraged. But Randall Cunningham helped change all that when he took the NFL by storm in the mid-1980s.

In the latest installment in our documentary podcast series Ahead Of Their Time, we examine how Cunningham frustrated defenses not only with his speed and agility but also with his ability to throw the ball. It was a combination of skills that no quarterback had ever really possessed before, and it helped Cunningham transform the way people thought about the game’s most glamorous position.

After flashing abilities as a passer, runner and punter at UNLV, Cunningham was selected in the second round of the 1985 NFL draft by the Philadelphia Eagles. And almost immediately, his unique skill set grabbed his teammates’ attention.

“You knew there was something special about Randall,” former Eagles defensive back Eric Allen said. “[He was] extremely athletic, played with a great sense of self, understood that he was good, understood that he could do a lot of things that other quarterbacks in the game could not do, and he had a great deal of confidence.”

Despite his talent, Cunningham sat behind Ron Jaworski, a more traditional dropback passer, for most of his first two NFL seasons. But he became Philly’s starter after Jaworski was hurt late in the 1986 season — and the Eagles’ iconoclastic coach, Buddy Ryan, soon let Cunningham loose as the game’s first true dual-threat QB.

“Buddy Ryan allowed me to be the player he believed I could be,” Cunningham told me. “He saw something in me and gave me an opportunity to flourish as an athlete, and not just a quarterback, but to really take it to a whole other level.”

Cunningham wasn’t the first mobile QB in NFL history. Before 1986, six quarterbacks had put up 500 or more rushing yards in a season; in 1972 alone, two of them — Bobby Douglass of the Chicago Bears and Greg Landry of the Detroit Lions — combined for a whopping 1,492 rushing yards and 17 rushing touchdowns. Those were the two best pre-Randall QB rushing seasons according to my yards above backup QB (YABQ) metric, which assigns a value to a quarterback’s passing and rushing statistics in a way similar to Football Outsiders’ yards above replacement (and can also be calculated throughout history). But Landry’s days as a scrambler were limited — he only had a couple more 200-yard rushing seasons in his 15-year NFL career — and Douglass, as great as he was running the ball, couldn’t throw. There was the occasional outlier, like Minnesota’s Fran Tarkenton, who was a strong passer and able scrambler, but before Cunningham, those players were seen as unicorns more than archetypes.

Cunningham ushered in the age of the running QB. In 1987, his first full season as Philadelphia’s starter, he passed for 349 more adjusted net yards than a backup-level QB (16th best in the NFL that year) and rushed for an additional 125 yards above backup (which easily led the league). It was the third time in history a quarterback had hit both of those benchmarks in the same season, after Landry in 1972 and Steve Grogan with the New England Patriots in 1978. And Cunningham was just getting warmed up.

In 1988, he piled up 336 YABQ through the air and 171 on the ground, the first time in league history that combination had ever been achieved. In a “down” 1989 season, he notched 248/147, a combo that had only been reached twice before (by Landry in ’72 and Cunningham himself in 1988). And in 1990, Cunningham set a standard for dual-threat seasons that has yet to be eclipsed in the 26 years since. That year, he was 750 yards better than a backup through the air, and he tacked on another 249 YABQ on the ground; if we take the harmonic mean of those two numbers (a particular kind of average that emphasizes high values in all numbers being averaged, in order to capture seasons when a player produced a lot of passing and rushing value), it’s the single best combined passing-rushing season by a QB in the Super Bowl era:

YARDS ABOVE BACKUP PLAYER YEAR PASSING RUSHING HARMONIC MEAN 1 Randall Cunningham 1990 750 249 374 2 Robert Griffin III 2012 847 218 347 3 Russell Wilson 2014 659 225 335 4 Michael Vick 2002 679 218 330 5 Michael Vick 2010 860 202 327 6 Cam Newton 2011 512 224 311 7 Cam Newton 2012 608 195 295 8 Cam Newton 2015 633 169 266 9 Steve Young 1992 1,737 142 263 10 Greg Landry 1972 547 167 256 11 Steve Young 1998 1,474 133 244 12 Daunte Culpepper 2000 1,558 129 239 13 Kordell Stewart 1997 422 159 231 14 Rich Gannon 2000 947 129 227 15 Randall Cunningham 1988 336 171 226 16 Michael Vick 2011 593 140 226 17 Steve Grogan 1978 484 146 224 18 Steve McNair 1998 450 149 224 19 Daunte Culpepper 2002 288 181 222 20 Kordell Stewart 2001 610 132 217 21 Randall Cunningham 1992 445 144 217 22 Tyrod Taylor 2015 682 129 217 23 Colin Kaepernick 2013 803 125 216 24 Cam Newton 2013 423 143 213 25 Donovan McNabb 2002 419 141 211 26 Donovan McNabb 2000 232 178 201 27 Greg Landry 1971 861 113 200 28 Russell Wilson 2012 952 111 199 29 Steve Young 1991 1,030 110 199 30 Steve McNair 2001 1,102 109 198 Greatest dual-threat QB seasons, 1966-2016 Source: Pro-Football-Reference.com

There have been better pure passing seasons by mobile QBs; Steve Young had more than a few of them. As Cunningham told me, “People cannot forget about Steve Young, because [he] and I were battling out every single year to be the No. 1 rushing quarterback.” There have also been better QB rushing seasons; in 2006, Michael Vick became the first quarterback to break the 1,000-yard barrier in a season, though his passing was below the backup level that year. But nobody combined the two aspects of quarterbacking in a more prolific way than Cunningham did during that magical 1990 season, one which earned him league MVP honors from the Pro Football Writers of America.

Alas, Cunningham would injure his knee in the Eagles’ 1991 opener, and miss the entire season. He returned in 1992 to produce what was, at the time, the sixth-best dual-threat season in modern history (according to my method above), but ongoing battles with injury and inconsistent play eventually paved Cunningham’s way out of Philly in 1995. After a year away from football entirely, a rejuvenated Cunningham joined the Minnesota Vikings and, in 1998, he enjoyed the 25th-best passing season of the Super Bowl era, according to YABQ — a testament to his skills as a pocket passer after his athleticism had eroded with age and wear.

Cunningham finished his 16-year NFL career with the 40th-most total YABQ of any quarterback since 1966 and the second-most rushing YABQ — trailing only Vick. (He also generated about twice as much value through the air as Vick did.) But Cunningham’s biggest football legacy might be in the number of dual-threat QBs that followed in his footsteps. Before Cunningham’s 1987 season, only four quarterbacks had produced at least 200 passing and 100 rushing YABQ in the same season: Tarkenton, Landry (twice), Grogan and Doug Williams. Afterwards, 16 different quarterbacks pulled off the feat in 36 seasons, not including Cunningham himself. And 21 of the 25 best dual-threat seasons in modern history have taken place since Cunningham’s banner 1990 campaign.

There are still quarterbacks in today’s NFL who play like the traditional archetype of the drop-back passer. But there are also a number of top QBs whose playing styles resemble that of Randall Cunningham. By proving that a quarterback could dominate the game with both his arm and his legs, Cunningham opened up a new path to success for subsequent generations of signal callers. So anytime a passer rolls out and fires a dart to a receiver who broke free because the defense was worried about the QB running, remember that in some small way, that play was made possible by the influence of a Philadelphia Eagle who changed the game three decades ago.

This is part of our new podcast series “Ahead Of Their Time,” profiling players and managers in various sports who were underappreciated in their era.