These are the returning-to-school guys that
my formulas like. Note that my formulas are designed for incoming NFL players rather than for guys in the middle of their college career, and will especially miss out on guys who were stuck in a smaller role behind talented upperclassmen (and guys whose measurables are estimated inaccurately by nfldraftscout). Each list goes from highest rated to lowest rated in that category. Some of these guys won't be draft eligible in 2018.
Top RB prospects: Derrius Guice, Nick Chubb, Royce Freeman, Saquon Barkley
Decent RB prospects: Rashaad Penny, Ty Johnson, Mike Weber, Ray Lawry, Kerryon Johnson, Damarea Crockett, James Butler, Lavon Coleman, Damien Harris, Benjamin Snell Jr., Rawleigh Williams III, Jarvion Franklin, Kalen Ballage, Phillip Lindsay, Ito Smith, Bo Scarbrough, Kyle Hicks
Top WR prospects: Courtland Sutton, Equanimeous St. Brown
Decent WR prospects: Cody Thompson, James Washington, Jester Weah, Nick Westbrook, Jonathan Giles, Anthony Miller, Michael Gallup, Richie James, Cedrick Wilson, Darren Carrington
Top QB prospects: Baker Mayfield, Sam Darnold, Logan Woodside
Decent QB prospects: Mike White, Jake Browning, Deondre Francois, Mason Rudolph, Austin Allen, Brett Rypien, Lamar Jackson
The top prospects at each position would rate as good prospects (or better) if they were entering the draft right now. The top QBs already rate ahead of any of the QBs in this year's class (though the QB ratings are only based on production, not measurables or scouting, and needs to be supplemented with other info moreso than at other positions). The top RBs are already up there near the RBs entering this year's draft, though they're still a bit below. The top WRs are farther behind this year's top prospects, more in the range of what I'd expect to see from 2nd or 3rd rounders. The bottom of the "decent" tier for each position is more like "just worth keeping on eye on"; their ratings aren't high enough to be be very promising if they were entering the draft right now.
On the whole, things for 2018 look worse than they did
a year ago for 2017. The WRs don't have an elite prospect (the way that JuJu Smith-Schuster looked to be a year ago) and the top 4 RBs don't look quite as good as last year's top 4 did at this time (Chubb, Fournette, Freeman, Cook).