Defensive back is always the toughest position to rank for me every year. The scheme changes and shifts in the depth charts can make it difficult to see which players will flourish. This year is no different.
There are quite a few position battles at strong safety on teams that project to have productive safeties from an IDP standpoint, so it's certainly not far-fetched to think some gems will be unearthed on the waiver wire. Generally, I'm going to grab an elite safety once they start coming off the board. Linebackers seem deep enough where I'd feel comfortable waiting, but if you need to have two defensive backs, you might not want the first wave of the DB rush to pass you by.
As usual, there has to be value in selecting your DBs. I am never the first person to take a DB and as much as I love Kam Chancellor this year, if someone else agrees with me and wants to take him as the first DB, then good luck.
For more info on individual defensive players, check out my IDP post on defensive linemen from earlier on Sunday. There are a lot of weird formats out there covering defensive players. Ask me anything you want on Twitter @MikeSGallagher.