I really like the intent of this post, as it poses a question attempting to provide insight into uncovering the characteristics of a great RB. I think the OP gave a pretty vague request, however, by simply stating "who are the elite physical talents" at the RB position. Without some sort of criteria, or "point of reference" from which to measure, you will certainly get varying opinions as to how people interpret the question. I like how SSOG broke it down into different categories, even though I disagree with several key points he made, Peterson is a physical marvel, on the level of just about any RB to ever play the game. Looking at many of the physical and instinctive traits critical to RBs, his size/speed/agility/overall athleticism/power/balance/vision combination is phenomenal.
For me, it comes down to a point of reference, or a measuring stick. An elite RB, IMO, is primarily based on instincts (vision, awareness, anticipation, patience, jukes/wiggle) and athleticism (strength/power, burst/acceleration, agility, top-end speed, balance), combined with the determination and drive to not be denied. The truly elite guys don't necessarily require the greatest of blocking, and they often have defenses stacked just to contain them, yet they still succeed to levels of greatness. They are what I deem "pure runners". It's not that easy to fully describe, but there is a quote from one of the greatest "pure runners" of all-time that sums it up quite nicely......."Just give me 6 inches of daylight, that's all I need" - Gale Sayers.
Back to my "point of reference", and for me, I ask the question, who are the guys who simply have the abilities to take it to the next level of performance, when all other things are pretty much considered equal? Give them an inch, they take chunks of yards, give them inches, they make "magic". My ultimate point of reference, or measuring stick, for "pure runners" is Barry Sanders.
One thing that I'll state is that I believe the elite athletes that rely mainly on true, brute force, I don't consider them to be elite physical talents, especially with regards to RBs in this category that I'm explaining, the "pure runners". So the Brandon Jacobs' of the world, nuh-uh.......
Other guys who I've seen mentioned in this discussion who couldn't crack my list are Steven Jackson, MB III, and Michael Bush. Again, no disrespect to any of these players, all fine football players and great athletes, but "pure runners" are special guys, born to run the football and they are electric with the ball in their hands.......And lastly, I do stress "game speed", you gotta be able to go the distance, otherwise, your upside is limited, IMO, and I think that the OP definitely intended for upside to be part of the criteria. Best "pure runners" in the game today, in order.....
1. Adrian Peterson......UNQUESTIONED, clear as the sky is blue. If you can't see this one, then you just don't know and probably never will.
2. DeAngelo Williams.....Yep, probably threw many of you for a loop here, but this kid is tremendous, makes something out of very little on a regular basis. One small caveat though, he is simply keeping the #2 spot warm for the next guy on my list
3. Felix Jones......One word, ELECTRIC!.....Once he hits the field this year barring a significant amount of missed time due to injury, even in a RBBC, he will shine as bright as anybody in the NFL. Barber will be regulated to 2nd fiddle by the end of the year, if not sooner. Don't be surprised to see close to 6ypc with 180+ carries, translation, 5.7 or better.
4. Chris Johnson....Unmatched burst/acceleration, but instincts, although Johnson's are very good and top-level, his are not on the level of the 3 guys listed above him, and that is why they are ranked higher here.
5. (tie) MJD.......Pocket Hercules is a scoring machine, a little ball of dynamite who is extremely tough to tackle and ultra-instinctive. But another thing that I question with regards to earlier comments is the sub-4.40 40 attribute. I really doubt this, and even if it's true, his game speed does NOT reflect a sub 4.40 40. In comparison to Felix, who clocked a 4.44 or so, Felix plays much faster than MJD. Not a knock on MJD, just a realization and one reason for the given rankings.
Larry Johnson (LJ).....Surprise! Again, the mantra is "pure runner", and even now, LJ still has "it". "It" may not reflect in his final statistical numbers this year, but the guy still can run like few others. If given the carries, he will get the yards at a very nice clip. From what I witnessed on film last season, the guy still has the vision, cuts, balance, and most importantly to keep him on this list, the burst/acceleration. After this season, he may fall out of these ranks, but who knows what's in store for LJ this year? It's all about the touches, the talent is still there in spades....
Well, I'll stop right here and with all due respect to some greats still playing who would've easily made this list only a couple of years ago, LT, Westbrook, and Fred Taylor, this is not a legacy list. This is about right now, and going forward from this point who I believe have the "goods" to take it to the next level of performance.