I went over the Fantasy Football Today team's first quarterback rankings after the NFL Draft on Tuesday,  and while I'm sure that was exciting, we all know you don't really care about 30-plus quarterbacks for Fantasy. There's maybe 20 or so who matter -- and really, it's only like seven or eight who truly matter.

At running back, it's a different story. To some degree, every running back matters. If you're starting, we're making start/sit decisions about you. If you aren't starting, you're a sprained ankle away from being the most over-scrutinized player of the week. Running backs aren't necessarily always the highest scoring players, and you might not even start more than two of them in any given week, but because the position is so fungible -- there's just so much change week over week, let alone year over year -- it occupies an inordinate amount of our attention.

It's also the position where May rankings may be least predictive. Opportunity is king at running back, and there are plenty of spots where we're still guessing who will get the opportunity to be a Fantasy difference maker. As I continue to move through our post-draft positional rankings, just keep in mind that, while this establishes our first estimate at some baseline expectations, much of this can and will change by training camp, let alone once they put the pads on. 

For now, here are the consensus and individual rankings for the running back position for 2021 from Jamey Eisenberg, Dave Richard, Heath Cummings, and myself. If you've got questions about the rankings or have any questions about your own team, hit me up at Chris.Towers@CBSInteractive.com to get your answers. And now, here's the state of the QB position as of May 5. 

We'll move through the top 35 backs 12 at a time, and I'll highlight some individual rankings that stand out. 

RB Rankings, 1-12

• No surprise at No. 1, and no disagreement. Even after missing most of last season, Christian McCaffrey is the consensus top choice. Don't be scared off by the injury, and don't forget that, whatever you think of Sam Darnold, McCaffrey put up historic numbers in 2019 with worse. He's the easy call at the top of all drafts.
• Not much disagreement at No. 2, either. Dalvin Cook is probably the only back you could realistically see getting 20 carries per game besides Derrick Henry, and he's involved in the passing game, too. And, besides a few minor issues, he's had a pretty clean bill of health over the past couple of seasons. 
• But Alvin Kamara, now there's some disagreement, though probably not as much as it seems between Heath, who has him sixth, and myself and Dave, who have him second. I think it might just come down to this: Heath is projecting Taysom Hill to start, and I'm not. If Hill starts, Kamara will probably move down closer to five, but I'm hoping it's Jameis Winston under center when things kick off. The Saints will pass more with Winston and, because he won't scramble nearly as much as Hill, he'll look for Kamara even more often.
• There's pretty broad consensus across the rest of the top 12, but I'm stubbornly lower on Derrick Henry than everyone else. I don't feel good about it, because he's handled unbelievable workloads over the past two seasons without slowing down. But, ultimately, it comes down to a math problem: Catching passes is just so valuable in Fantasy. A player who rushes for 100 yards and a touchdown each week can be outscored by a guy gets 60 rushing yards, a touchdown, and catches 3 passes for 11 yards. When you catch as few passes as Henry does, you need to be better than everyone as a runner. Henry has been over the past two seasons, but if he's just the third-most productive runner in the NFL, he probably returns more like second-round value. 
• It'll be fascinating to see what happens with Austin Ekeler, who has seen massive target volumes in the past under Anthony Lynn -- he was on pace for 94 catches in his eight healthy games last season. Ranking him fourth, I'm betting the Chargers continue to feature him heavily in the passing game, and with the departure of Hunter Henry, I think it's a good bet. 
• I suspect all four of us may be lower on Nick Chubb than the industry consensus, but Heath and I are especially low. The answer for why is obvious, and it's what I said about Henry: Because Chubb doesn't get targeted in the passing game much, he has to be one of the two or three best rushers in the league to justify a first-round kind of cost. The difference between him and Henry is, Henry isn't sharing work with another back who could be a top-10 back if he was the feature back. The margin for error for running backs who don't catch passes is just so slim. 

RB Rankings, 13-24

• One thing to keep in mind about this range is, the difference between, say, RB13 and RB20 may not be that much. In my projections, it's the difference between 15.6 PPR points per game and 14.5. That's not nothing -- and obviously my projections are but one man's moderately informed opinion -- but at least in my eyes, these differences just aren't that great. I think there are about 24, maybe 25 running backs I would legitimately feel OK with as my starters in Week 1. So, when I'm arguing for one back over another in this range, just know I can be pretty easily swayed. 
• I don't know how I became the low guy on D'Andre Swift, I really don't. In my first run through the projections, he was a top-10 guy for me. I think the biggest thing is, I only have him getting 52 catches, while I think the assumption is he could be more in the 70-plus range. That's definitely possible, especially with Anthony Lynn, Ekeler's format head coach serving as Detroit's offensive coordinator. And given the Lions receiving corps being what it is, I also think he might be in something like a 65-35 split with Jamaal Williams , who got a decent contract and is a solid all-round player with three-down skills himself, if not a game-changing talent like Swift. And if the Lions offense is as bad as we think it will be, there may not be many touchdowns to go around. 
• I am higher than the consensus on Steelers rookie Najee Harris, which is mostly a bet on him getting Le'Veon Bell/James Conner role where he sees 80% of the RB touches. For as ugly as Pittsburgh's offense was at times, the Steelers still scored plenty of points. This can still be a very good situation for an every down back like Harris, even if I think the offensive line may be an issue. If anything, Ben Roethlisberger's newly conservative approach might make Harris even more valuable.

RB Rankings, 25-36

• This is where the drop-off is. For me, it happens right at the cut-off between No. 2 and No. 3 running backs. Generally speaking, everyone in the consensus top 24 would be fine as a starter for me. 
• After that, it gets tricky. I would be OK with Melvin Gordon as a starter to open the season, for example, but I suspect rookie Javonte Williams is eventually coming for a significant chunk of the playing time there, so I wouldn't want to rely on Gordon forever. 
• And the closer you get to the 30s, the less confident I am. David Johnson or James Conner or Chase Edmonds as a starter? I'm not feeling great about the workload or talent for any of them. Leonard Fournette? In an offense as crowded as Tampa's? Yikes. Truth be told, my strategy is going to be fairly simple: I want two running backs in my first three picks if I can get them -- with a tight end as well, optimally. And if I can't get one of my top 24, I'm probably going to wait until Rounds 7 and later to start acquiring my No. 2 and depth options. Your mileage may vary, but the middle class of running backs are typically the worst investments you can make in Fantasy.

The rest of the consensus rankings

37. Devin Singletary
38. James Robinson
39. Tarik Cohen
40. J.D. McKissic
41. Jamaal Williams
42. Giovani Bernard
43. A.J. Dillon
44. Latavius Murray
45. James White
46. Damien Harris
47. Tevin Coleman
48. Ronald Jones
49. Tony Pollard
50. Gus Edwards
51. Trey Sermon
52. Jeff Wilson
53. Alexander Mattison
54. Darrell Henderson
55. Kenneth Gainwell
56. Rashaad Penny
57. Darrynton Evans
58. Darrel Williams
59. Phillip Lindsay
60. Sony Michel