I have no problem with the anti-FO hijack 
As you mentioned, VarlosZ is the guy who brings them up most of the time, and he introduced me to them too (though I didn’t buy the book). I tend to see them as a helpful reference at times - they look at the NFL in a way that I wish more people looked at the NFL, even though they aren’t perfect. That sort of statistical approach works a lot better with baseball in large part because baseball has simply been keeping a lot more statistics for a lot longer - and even THEN we are constantly needing to invent new ways to evaluate fielding. I think the NFL could use that sort of scrutiny, but a major problem is always trying to decide what metrics to use for a given situation. I wanted to go more in-depth with my own numbers, but as you allude to, it’s near-impossible to even find a lot of that stuff online, and god forbid you want to go back more than a year or two. Then again, I suppose it took us long enough to get fantasy football leagues to realize that yards might have importance along with just TDs, and we aren’t completely there yet. So any progress is good progress, or something.
Conceding Kiros’s caveat that Bailey may only be very good instead of great, I agree with every word that Jimmy Chitwood typed in this thread. He’s speaking the gospel from on high.
Most draft experts, led by Mel Kiper, will tell you how you shouldn’t waste a first rounder on a RB because so many of the later-rounders go on to have great careers.
There are more quality RBs than there are quality CBs in the league, and twice as many CBs on the field at any one time. Clearly quality CBs are far more precious than quality RBs.
To pursue the anti-FO hijack, they piss me off to no end with their “it’s random so therefore meaningless” bullshit. Fumble recoveries are random because teams aren’t consistent in their ability to get them across seasons. Guess what? So are interceptions, and so are field goals, and so are any number of things in football. This in no way demonstrates that they are random or “unachieved” in any way.
That claim pissed me off from the moment I read it, and has pissed me off more and more over time. Even worse, they admit that individual fumbles aren’t random. (Behind the line, more likely the offense will recover. Downfield after the catch, more likely the defense will recover.) But when added together, these non-random events combine to produce seemingly random totals. GAH! That randomness is a limitation of your stats, not a reflection of reality!
You can spend practice time stripping balls. You can also spend practice time recovering loose balls. These are skills that can be honed. You can have a more disciplined team that has a nose for and/or swarm to the ball. You can have guys well trained to fall on the ball instead of trying to pick it up and run. You can have your running back alter the way he holds the ball. You can improve your OL so your QB doesn’t repeatedly cough it up from getting killed all day. All these factors play a causative role in your fumble recovery production. According to FO, though, fumble recoveries are unearned because they are all and always completely random.
Look at Tiki Barber. The Giants have recovered half his fumbles throughout his career. (Oh no, 50%…must be RANDOM! Their heads might explode if you point out a passer with a 50% completion rate.) His fumbles nose-dived in 2004, so obviously the Giants were missing a significant amount of fumble recoveries. This is just one example of a clear cause-and-effect relationship between a team’s skill-set and fumble recovery production varying from year to year, and yet FO dismisses all such examples, citing the varying production as evidence that it’s all just random.
Apart from this peeve of mine, I also agree with Jimmy’s other complaints about their analysis. Their execution is as flawed as their intent is laudible. (But their power rankings are less worthless than opinion polls, so that’s a big plus.)
The point about more good RBs than CBs is all well and good, but one thing that makes this discussion difficult (and interesting) is that its really hard to evaluate the impact of a CB. As has been accurately noted, you could watch an entire game and never hear a CB’s name, and that might be a good thing - that CB has shut down his receiver - or it might just mean they never threw in his direction for a variety of reasons. A CB could have 2 INTs in a game, return them both for touchdowns, but also get burned for 3 long TDs and his stats may not reflect that. Its interesting that the comparison to baseball stats was made.
I posit that baseball’s stats more accurately reflect a player’s worth to that team than football’s - not because they have been kept longer or analyzed more (although thats part of it), but because football has a lot more subtlety in terms of an individual’s actions and the overall impact on a team. A wide receiver block downfield that never gets recorded anywhere but springs an RB for a touchdown has a huge impact on that game, but if you look at the final line all you will see is the RB’s numbers. Gregg Easterbrook (who’s espn page2 column I enjoy a lot) calls them Hidden Plays, and he usually highlights at least 1 a week. I just think football is more of a crapshoot than baseball, statistically speaking.