Whoops....Should be "no" effect on reaction time.
It is my conclusion that ratings ultimately do not matter on an individual level outside of such ratings as speed; speaking just as far as DB and WR interactions, most definitely, because I haven't bothered to test all positions and ratings.
From what I have gathered I agree that 91 is the threshold of actually being good at zone or Man coverage, but man is tricky, it doesn't help much in actually covering routes but you will get more hits that cause dropped passes or knock outs on such routes as outs and ins.
Streaks is really the only route that man cover should even be used as the DB has a 50/50 chance of making a play; usually a breakup. only other time where a DB has a chance is if the WR is severely less in ratings than the DB, which just doesn't really happen in madden.
I have tried this using the same team, so the overall was the same, using the Rams; then I used the rams on offense against the 91 overall chiefs, and coverage was much tighter and better, so I believe that the overall team rating affects the individual ratings..
I also believe this because in MUT the CPU teams will have "x" number of players at a given rating, lets say 90, and then all the other players could be in the 70's, but yet those players in the 70's play better than if the team had those same key players at 85. Essentially, building a team because of how ratings appear to work, you just need high rated players in the key positions like:
QB1
HB1
WR1
C1
LT1
TE1
CB1
S1
MLB1
DE1
and then just fill the rest of the positions with players in the 70's with the highest possible physical ratings like spd, acc, agi, etc and u would be fine.
(but anyway this is off topic)
I do hope that if run/pass commit is removed that they can add in more options for deep blue zones. I think if a person is going to user a player it is best to user a safety because they are the ones that generally have no run fit assignment, outside of Cover 4, while still allowing full view of the offense unlike trying to play CB.