Al Willman Special to The Detroit News

First in a series.

There were 89 quarterbacks on NFL rosters at the end of the 2015 season but no one school stood out as significantly better than the rest at producing signal-callers, according to Detroit News research.

The University of Southern California led the way with four quarterbacks, and five schools, including Michigan State, had three each. Forty-eight schools produced one QB, including non-traditional powers such as Vanderbilt, San Jose State, Old Dominion, Alabama-Birmingham and even Harvard.

So while Southern Cal can still claim the unofficial title as “Quarterback U,” it’s clear there is a wide diversity of schools from which NFL teams draft and acquire quarterbacks.

One possible explanation for this diversity is the proliferation of spread offenses in college football. While spread offenses — which often require a quarterback to be adept at both throwing and running — have flourished in the college game, NFL teams still place the highest value on traditional dropback quarterbacks.

Some college quarterbacks are even asked to line up at wide receiver occasionally.

"Most cases now, they want a quarterback to be able to do both — to run and pass,” Detroit Mumford offensive coordinator Deon Godfrey said. “The day and age of just a dropback passer, while there are certain colleges that are a fit for that, nine times out of 10 (dual threat) is what they’re looking for.”

Godfrey said many of the schools across the country he interacts with want quarterbacks to be taller than 6-foot.

And if a quarterback is under the 6-foot threshold?

“The further away from six feet you are, the closer to 4.3 (40-yard time) you need to be,” Detroit East English coach Rod Oden said. “So, you need to be faster if you’re going to play under six feet.”

Godfrey also pointed out that it’s not unusual for a dual-threat college quarterback with exceptional athletic ability to transition to another position in the NFL. Take, for example, former Michigan quarterback Denard Robinson, who now plays running back for the Jacksonville Jaguars, or former Indiana quarterback Antwaan Randle-El, who played wide receiver in the NFL for Pittsburgh and Washington from 2002-10.

“Most of our quarterbacks (in high school) end up changing positions,” Godfrey said. “They want to be sure that they’re reading defenses and things of that nature.”

But what it all boils down to is fit. High school and college coaches agreed that the most sought after player in the NFL isn’t always the one with the most talent. A great quarterback is able to be a good teammate, and is coachable — at any level.

“Obviously, they’re trying to find what projects to be the best football player in the NFL,” Eastern Michigan coach Chris Creighton said. “They’re measuring arm length, they measure the size of their hands. I mean, they’re still looking for growth potential, just like we are with 16- or 17-year-olds.

“I think the thing that (most fans) don’t know is how thorough they are in checking character and what kind of teammate they are. That matters at every level. We’re trying to find people who are going to fit who we are and what we’re trying to do. It’s really difficult trying to figure that out.”

Al Willman is a freelance writer.

Football recruiters hit paydirt in three states

About this series

To find out which states and conferences produced the most football talent, The Detroit News created a database of the season-ending 2015 rosters for every NFL team.

Detroit News series

Southern Cal earns title of 'Quarterback U'

Big Ten producing O-linemen for NFL, but SEC sends more

NFL WRs mostly come from California, Florida and Texas

Penn State upholds linebacker tradition

California, Stanford have most running backs in NFL

Alabama top producer of NFL defensive backs

SEC dominates in sending defensive linemen to NFL