Well, as (someone more senile than) John Madden once said, there are known knowns, known unknowns, and unknown unknowns surrounding both these players. In terms of assessing them, I just can't find much difference between them.
But I'll try to break it down, Dr. Jack style:
TRACK RECORD. Edge has 9000+ rushing yards and 60+ TDs. Ronnie has 907 rushing yards and 4 TDs. Edge has been a featured #1 RB for years, Ronnie has been one for four games. Strong edge EJames
INJURIES. Edge has missed games here and there over the course of his career, and missed ten games in 2001 (knee). Ronnie seemed a little dinged up at the end of last year, and didn’t play Week 16. This is a known unknown: how will Ronnie hold up playing an entire season as a featured back? Because we know Edge holds up fairly well—he has put together multiple seasons without significant or performance-harming injuries—he gets the nod. Slight edge EJames
OFFENSIVE LINE. I don't think this one needs much analysis. Strong edge RBrown
SCHEDULE. Both AZ and MIA play pretty light schedules, with MIA’s lighter on paper. However, I think the ease of MIA’s schedule is a bit exagerrated. I expect a significantly better defensive year from the Pats, and an improved defense from the Jets. Sooo, Slight edge RBrown
TEAM PASSING OFFENSE. Needless to say, the AZ passing offense is very strong, with a proven QB passing to a pair of proven stud WRs who complement one another nicely. And, frankly, I'm not sold on the MIA passing offense. Culpepper is coming off a catastrophic knee injury, and while all reports are that he has made a dramatic recovery, if he recovers his 2005 form, he'll be among the worst QBs in the NFL. He really needs to recover his 2004 form, which, given MIA's WRs after Chambers, is far from a given. So this would be a strong edge to EJames, but I think you have to factor in Warner's fragility and that he has a (albeit talented) rookie backup. Edge EJames
UPSIDE. I think at this point we know what Edge can do: We’re looking at 1500 – 1600 rushing yards, 10 or 11 TDs, another 300 or 400 yards and a TD in receiving. It’s hard to believe he’ll exceed what he’s generally done on IND with AZ. Ronnie’s upside looks to be pretty high—which is a big part of his appeal. His ceiling is another known unknown.
To watch him play, he seems to have all the skills and talent to match what Edge can do. And he’s obviously in a position to succeed in MIA: featured back, good OLine, etc. So how do you measure a 2000/12TD ceiling (seems reasonable for Edge) against a string of question marks? To use the crudest tools, you could take his YPC (4.4) and multiply it by his and RWilliams’ 2005 total carries: that gives you 1650 yards. Pretty close to Edge, and that’s probably the best you reasonably can expect out of Rbrown. Wash
INTANGILBES. Here’s the thing: I hate a guy in the first year of his new mega-contract. Hate, hate, hate it. Compare that to a guy who has a chance to make his career in the NFL… Edge Rbrown
FINAL ANALYSIS. Well, when you look at the whole thing, it’s hard to get closer than that—they pretty much have equal pluses and minuses, depending on how you weigh the various criteria for comparison. If you held a gun to my head (and I encourage you not to), I’d have to say I’ll take the guy who can have an average-by-his-standards season and match the best-you-can-expect season of the other guy. The problem, of course, is that an average season from Edge would be by far the best AZ RB performance in recent memory. Still, I don’t think AZ’s problems are on the offense. Kensat’s right, a fantasy back should be happy in AZ, even with the offensive line issues.
Slightest of edges to Edge.