This is the first year I've done a regular ranking of the rookies, and I'm finding that in some ways it can be even tougher than pegging the best prospects. With prospects, you try to separate what you're seeing with what a player is capable of. If I see an undersized defensive end who isn't holding up well against the run but has special quickness and pass-rushing skills, there's a good chance he's an outside linebacker at the next level. I'm projecting. His grade isn't just about performance; it's about what he can be.

It's a different story with NFL rookies. Most rookies are being used to maximize their skills. I consider the players around them and how much help they're getting, but these rankings are about pure performance, not just potential.

Again, the usual parameters:

• The rankings reflect play over the whole season, not just the previous Sunday.

• Positional value matters, but overall performance and impact on the team matter more.

• I'm asking: Would this player be a starter on most teams? (I think that hurts QBs some).

• Total snap count matters. Great plays matter, but staying on the field is important.

With the rules in place, here we go. This week, I decided to go 35 deep:

Richardson

1. Sheldon Richardson, DT, New York Jets

He's been a solid, steady performer week after week for the Jets. It's interesting to note that Richardson is the top rookie defensive lineman in the NFL right now and former Jets first-rounder Muhammad Wilkerson is right there among the top overall defensive linemen in the NFL at this point. Richardson is particularly dominant against the run, with great vision and a sense of where the ball is headed. Rex Ryan has to be thrilled with the line, and second-year man Damon Harrison has also been outstanding.