Tier rankings for 2015 NFL draft

We have ranked prospects for the 2015 NFL draft since last summer, and are providing our final update with our Top 300 on Wednesday. But another tool that I find valuable every year is our draft tier rankings, which identifies the different levels of talent drop-off in this class. This can help when comparing players who are close to each other in the rankings. It also helps with predicting where players will come off the board during the first three rounds of the draft.

Here are our draft tiers for 2015, covering players with first-, second- and third-round grades (which are in parentheses next to each player's name):

Tier 1

This is the elite class of prospects in the 2015 NFL draft. They should be starters from day one and project as perennial Pro Bowl players.

1. Jameis Winston, QB, Florida State (Grade: 97)
2. Leonard Williams, DE, USC (96)

Tier 2

A notch below the elite class, but still worthy of a top-10 pick in most drafts.

3. Amari Cooper, WR, Alabama (94)