It's pretty obvious that you have to get physical with the receivers in order to disrupt these passing offenses. Problem is a lot of teams flat out don't have the personnel to play hard man coverage like that.
Also, the average wide receiver is getting bigger while the defensive back is still averaging around 5'10". It's too easy for quarterback to just lob it up and have the big physical receiver retrieve the ball. You can't tell me that quarterbacks are reading the defense on a fade route at the back of the endzone right at the snap.
Earlier in the year I read a very well done piece on off man coverage and how it may be the start of a new trend.
Theory goes that you're rerouting receivers just by being in front of them, can slow them down with proper technique/hip control.
Playing off man allows you to disguise your coverages better, especially blitzes. If the secondary is virtually at a standstill and not declaring press it's hard to figure out if it's man or zone.
You have to rely on you corners properly paring QB drop with the corresponding routes. So with a 1 or 3 step drop, you're only going to defend a couple of routes like a quick hitch, quick out, slant or drag. It's now up to the corner to decipher information, where is the receiver split and whats the most probable route based on the drop.
There were a bunch of Packer cutups associated with the piece, strictly off man coverages and they did a good job conveying the idea behind off man techniques. It really worked, but in the situations were it didn't, it was usually the safety jumping an underneath route, it really didn't burn them in the clips I watched however because the blitzes got home.
Revis is a great press corner, but he's pretty incredible in off man situations. Guy is just smart, recognizes routes on a drop pretty easily. There's a vid of him doing it in practice, fun to watch.
I would post but I'm on an iPad and I loathe the fucking thing, how does anyone get anything done on this thing.