I know that I added some confusion with my last dev chat on some of the topics. I'm going to add some of the lingering questions here and try to explain them a little better.
ZSAP Asked: There is still confusion on how defensive passing coverage works. In this excerpt by norbert on the beta forums he says LBs and CBs play man and Safeties play zones. Has this changed during your time here?
Answer: Things have not changed. The part that was confusing was I used the word Zone to mean something else. I shouldn't have said zone. Apologies. The question asked was can a specific DB be used to cover a receiver. What I meant is that the system does not have a concept of sides of the field, so the DBs can be on either receiver on any given play. The defender is chosen at the time the QB targets a receiver based on the likelyhood that the defender is in the current location of the receiver. Once they are chosen, they are used entirely in the calculations, or I guess what you could call our version of "man to man". The way the ZONE players work is that they are PARTIALLY added to the defense of that play, and can be added partially to other areas as well.
Hope that helps.
Here is the quote from norbert that was metioned:
For cover, you basically have 3 types of players - LBs, CBs, and Safeties. Safeties are also designated as SS and FS which is important. You also have the 5 possible target locations - Very Short (behind the line), Short, Medium, Long, and Deep (>20 yards). You can have 3 types of receivers - RBs, TEs, and WRs - along with their certain slot location distributions set on the formation which can be thought of as "routes".
The simplest way to look at this is: LBs will cover RBs and TEs and their routes. CBs will cover WRs and their routes. Safeties will cover zone locations based on the Cover settings. We all know how complicated football settings could be, so if you want to think of this in football terms, I would say this is closest to a Cover-2 with some adjustment on the Safeties play based on the Cover settings. The easiest explanation is that CBs and LBs play man coverage and Safeties play zones.
What this means is that CBs and LBs will tend to cover where their target goes, so even if you have Long cover, these guys will try to cover their players even if they go short. How well they cover them short can be adjusted, but they essentially don't just sprint down field because the Cover setting is Long.
While the CBs and LBs follow their receivers settings, the FS and SS follow the Cover settings. For Short cover, the SS will mostly play Short and the FS play Medium. For Medium cover, the SS will mostly play Medium and the FS split between Medium and Long. For Long cover, both will mostly play Long.