Who is the greatest running back ever?
Walter PaytonWalter Payton Nicknamed "Sweetness," Walter Payton is widely considered the greatest all-around running back of all time. He rushed for 16,726 yards which was an NFL record until 2002 when Emmitt Smith passed him. He's also fourth all-time with 110 rushing TDs.
What is the difference between a tailback and running back?
No other position has that unique distinction. Running back is general and can refer to Fullbacks and Tailbacks. Tailback refers to where the back lines up, in the Tail of an I formation.