What position did John Riggins primarily play?

What position did Larry Csonka primarily play? Larry Csonka is best known for playing with which NFL team? Which college was Larry Csonka playing for when he entered the NFL? What jersey number did Larry Csonka wear with the Dolphins? John Riggins is best known for playing with which NFL team? Which college was John Riggins playing for when he entered the NFL? What jersey number did John Riggins wear with the Redskins? What position did Tiki Barber primarily play?