Ill put in my 2 cents without reading the responses thus far..
best running back of all time, not yet, time will tell. If he stays healthy i think yes but hes had too short of a career thus far to say.
if the question was is he potentially the best.. I think everyone would agree yes.
now if you asked me if hes having the best running back season of all time? I would say absolutely (even if he doesnt break the record). I would even go as far to say hes having the best season of any nfl player of all time
it seems hard to compare players in the NFL because style of play, and the players themselves (bigger, faster, more film study, etc), change so much. Todays game is so much different than when Jim Brown player. Hell, its different from when Barry Sanders retired 15 years ago..
To me, the conversation should be more like 'Will Adrian Peterson be an Inner Circle HOF player?'
What a bum. Couldn't even get a measly record.