i'm not explaining myself clearly...
i meant to leave out extraneous non-rushing related factors like receiving or blocking... i realize blocking can be important to seeing the field, but usually supremely talented RBs find a way to see the field, even if they can't stone blitzing LBs... if they are so bad they get their QB put in the hospital it is a big problem (& as was noted above, may have been part of deangelo's problem in his first few years), but it seems that if a player is a enough of a physical specimen & athlete to be an elite RB, they probably have what it takes to be better than a catastrophic weakness in pass pro, assuming a modicum of application, willingness, attitude, competent instruction & coaching, etc...
westbrook is made a better OVERALL weapon by being one of the best receiving RBs of his generation (with marshall faulk), & can split out like a WR, but i am more interested in capturing how the SP views the relative RUSHING skills across the NFL RB-scape...
i didn't mean to include external factors that were supporting cast/surrounding talent-related... but i unwittingly intruded dynasty considerations with the starting from scratch remark (clumsily phrased for my intent)... so i would have done better to say, leaving out all extraneous factors like blocking, receiving & who they play with (or are in a RBBC), who would you want THIS YEAR... if you see LT/westbrook having no/little appreciable dropoff, rank them accordingly highly...
of course, that will contain dynasty-related information... depending on if you see LT/westbrook going up/down/sideways, you could have markedly different views on their value...
another factor that could be included is injury potential... not for the long term, but if you think a RB is more likely to miss some time THIS YEAR, dock him accordingly... my personal feeling is that predicting injury is a dark art akin to voodoo... however, if you look at steven jackson & see that he has missed a few games in a season a few times & hasn't been in the league that long, i could see how that might conceivably alter his ranking... there could be a difference (albeit maybe small) if he were more commonly viewed as an iron man, than if he never missed a game (perhaps jonathan stewart has some questions to answer, on that score)...
as to top RBs of all time, i wrote an article about my personal top 10 a few years ago & will see if i can track it down & if so will post here...
the best RBs i've seen (by this i mean film highlights in some cases), listed roughly chronologically...
jim brown - my father used to say the only reason i didn't have him #1 is because i never saw him, & i countered that i saw the highlights... eventually i came to agree, though... some RBs on this list are more well rounded than others... he was the complete package... size, strength, elite speed (for his time), vision, instincts, elusiveness... what maybe set him apart most (& he was already apart from his contemporaries just from above list) was his extreme competitiveness... & just a freaky, freaky athlete... probably could have been a pro basketball, baseball player, a boxer, even a decathlete with training... my favorite highlight was on one run when he lowered his head, bowled over TWO defenders, understandable lost his balance momentarily, had to spin while almost falling to the ground, than righted himself... dominant example of power, balance & athleticism...
gale sayers - not a long career, not a power back, but the best vision, instincts, moves & open field running ability i've ever seen, along with sanders... for me his signature play was when he had broke free & a defender closing on him from behind tried to sideswipe his head... even though it didn't appear from the angle of his head he could have SEEN him, he somehow FELT him, & ducked it at the last split second (maybe his periperal vision, maybe he heard/felt it like a ninja RB with heightened senses?)...
OJ simpson - in his time, great size, world class speed (don't remember if he ANCHORED USCs world record 4 X 100 relay team, but he was on it), all the other traits you like to see in elite RBs...
walter payton - i don't think he was as big, as strong, as fast, as elusive as some of the other RBs that populate this list... but he did EVERYTHING really well, he made the most of the ability he had maybe more than any other RB, & may have had the biggest heart... he may have had the best balance i've seen, along with sanders again (he seems to be coming up in elite trait comparisons a lot... hhhmmm

)... when i think of his signature traits, i think of him being like a human gyroscope, that would at times get knocked back (or more likely sideways, he didn't get knocked back often), would almost fall down, but would miraculously right himself from some impossibly crazy angles... needless to say, fun to watch... i also remember him for his toughness, & never running out of bounds... also, for his deceptively powerful upper body, & one of the more devastating stiff arms i've seen (when it wasn't nearly as common as it is now)...
earl campbell - guys that big just aren't supposed to move like that... his thighs could block out the sun... not sure if i've seen a LB get gored by a RB like isaiah robertson... his reckless, punishing, violent collision-friendly running style must have contributed to his short shelf life... he turned into a pumpkin by around 27, as i recall... his legs made him hard for LINEMAN to bring down, he was quicker & faster than most LBs, & his size & power made him a complete mismatch with DBs in the open field...
eric dickerson - like brown before him, he was sort of a mutant of his generation... certain people like magic (to illustrate from another sport) come along that are just, plain UNPRECEDENTED... before magic, there had never been (& still hasn't, probably, with apologies to lebron) a 6'9" dude with a handle like that & bob cousy-like virtuouso passing skills... dickerson was nearly as big as brown & faster (maybe a lot faster)... to my recollection, up to that that time, there had never been a RB that big that fast (or if you prefer, that fast, that big

)... i grew up in LA a rams fan, & it became obvious virtually immediately, fairly early in his rookie season, that he was a rare, special talent that doesn't come along often, & that he had a chance to become one of the best that ever played (he no doubt realized that formidable potential)... my favorite play was, & i'm not sure if it was the student body right, but he would sort of glide horizontally, letting the OL string the front seven out, & then he would wait for an opportune time/hole before seemingly instantly exploding through it... this highlighted & underscored his excellent patience, as well as vision & instincts... maybe because of his size or running style he didn't look like he was running that fast (robert smith was somewhat like this on the latter point, it looked like he was coasting/cruising), for a few years DBs had trouble dealing with his shocking speed for a big man & took bad angles... in the early years, it seemed like he didn't even have to reverse field, & scored many uncontested long TD runs straight up the field or down the sideline... some RBs with size aren't necessarily tough, but he was a handful that could also break tackles... i will always wonder whether if he had stayed with the rams great OL (slater, et al), he would have obliterated all the rushing yard records to the point where even emmitt wouldn't have touched him?
bo jackson - jackson upped the ante on dickerson, & was again unprecented in his time... legit 4.3 speed at 230 hadn't been seen before, i don't think... no idea what he could have done if he hadn't hurt his hip & divided his time/attention with baseball...
barry sanders - already talked about barry above... best balance & elusiveness i've seen (with payton & sayers)... quicker & more elusive than payton, stronger & more tackle breaking power than sayers... the only player i've seen in the history of ANY sport that moves like a cartoon character & seemingly routinely defied the laws of physics...
mashall faulk - phenomenal speed, quickness, shiftiness, moves... on this list, i won't exclude overall talent (best ever, period)... i don't remember lydell mitchell, who was before my time, but faulk was the first RB i recall that had good enough route running ability & hands that he could be deployed interchangeably with WRs, causing horrific mismatches for LBs & safeties... you almost needed a CB (& a GOOD CB

), to cover him... for a guy that wasn't that big, he was one of the best goal line runners ever (along with marcus allen), which speaks to his great timing, vision, instincts...
LT - in his prime, nothing he couldn't do... the total package...
peterson - 296 yards as a rookie... in some ways reminiscent of the way dickerson took the league by storm as a rookie, & also of bo jackson in terms of how superior a physical specimen & athlete he is... may be a more natural runner than bo, in terms of vision, instincts & elusiveness...
i forget if i had OJ in this previous list? pretty sure i didn't have peterson yet (it may have been before his rookie season)... i don't have emmitt here & i think i did before, so perhaps i've changed my thinking...
i don't have a problem with emmitt being highly ranked... it would have been interesting to see sanders behind DAL OL & smith reversed to DET... clearly smith would have done worse... for years in his prime, the OL (erik williams, nate newton, stepnowski?, among others) was so good that smith often wasn't even touched until he was 6-7 yards downfield (if that

)... but maybe it isn't that simple... smith was perfect for DAL style... sanders is a guy that might get caught behind the LOS two times (but probably less in DAL), than would bust a 70 yard run... so for aikman's surgical, methodical drives, you could make a case that emmitt was a great fit...
i used to underestimate emmitt (& maybe still do to an extent, since he isn't in my top 10 even)... but to give credit where credit is due, he had great short area burst (like jerry rice in the WR domain), thick & powerful lower body, great contact balance, phenomenal vision & instincts, & deceptive, underrated elusiveness (not sanders-like, but again, perhaps he was dissed because he did run through gaping holes at times... but when i looked more carefully & the holes shrunk, he still usually picked the right one & found a way to get through it)... almost everything but breakaway speed...
BTW, steven jackson & jonathan stewart are contemporary RBs that comprise very impressive size/strength/speed combinations...
* i don't buy the argument that deangelo couldn't be elite because he didn't take the league by storm in his first few years... if he is as good as i think he is & will be, i do concede it seems to be ODD, historically, & usually great backs assert themselves quickly/immediately... but if a basketball player didn't do much his first two years, & proceeded to average 40 points a game in the NBA for a season, we would have to take notice & say he looks like a genuine talent... in theory, you should be able to use your scouting lenses & break down their performance within the context of THAT SEASON...
** to those that think last years number of long TD runs by deangelo was flukey, i'd like to return to the sanders comparisons... williams also has powerful lower body, great balance, tackle-breaking power, great stop-start & cut-on-a-dime ability, great vision & instincts... but at least towards the end of sanders' career, he got dragged down from behind a lot (westbrook is not that fast, but has among the best first step quickness in the league at any position... at least, he used to?)... deangelo didn't get caught from behind too much... based on the visual evidence i was presented with last year (saw, not read), at least compared to later barry (not trying to avoid an apples to apples comparison by evading the comparable stage of their career evaluation, but stating it that way because that is when i remember sanders best, so that is what i can speak to), deangelo may have better wheels & be more dangerous & explosive in the open field in terms of finishing...