https://www.pro-football-reference.com/boxscores/196409200cle.htm

@calfoxwc said:

Frank Ryan. Very cerebral. I think he was pretty good at scrambling around in the backfield, but I was a young teenage Browns fan at the time. One of my favorite players back then was Gary Collins. Caught a lot of Ryan's TD's. My other favorite player was Leroy Kelly.

PhD in mathematics from Rice Univ. .    Sounds cerebral anyway.   

Also:  :  Archie Roberts wo played for the Browns, later got his MD  from Case Western Reserve

Blaine Nye  who played  DT for  a number of years for the Cowboys got his PhD in  Finance from Stanford.

And Charley Johnson,  QB for the St. Louis Cardinals...who gave the Browns fits,  got his  PhD  from Washington Univ. of St. Louis in chemical engineering. 

@the-gipper said:

Here is something to ponder:  Categories of Great QBs.    I will limit this to just those that played in the Super Bowl era:

Greatest Arm Talent QBs:    Aaron Rodgers,  Dan Marino,  Brett Favre,  John Elway,  Joe Namath,  Patrick Mahomes, Warren Moon

Greatest  Winners:   Tom Brady,  Joe Montana, Terry Bradshaw,  Troy Aikman

Greatest Cerebral QBs:   Peyton Manning,  John Unitas,  Drew Brees, Roger Staubach, Bart Starr, Bernie Kosar

Unique  Athletic talent or those with Chutzpah:  Fran Tarkenton,  Russell Wilson,  Steve Young, Cam Newton, Doug Williams, Ben Roethlisberger

Who did I miss? 

Frank Ryan. Very cerebral. I think he was pretty good at scrambling around in the backfield, but I was a young teenage Browns fan at the time. One of my favorite players back then was Gary Collins. Caught a lot of Ryan's TD's. My other favorite player was Leroy Kelly.