4-deep Invert Coverage

Agree with Oneback, as usual. You can also make a "CLOUD" call and rotate the corner down, with safety over the top (to the outside 1/3) this is a nice change up to the boundary side (it is a long way for the safety to go to the wide side). Some teams will use their WR to block that playside safety, your CB may come up unblocked and make the play (OLB/DE spills it to him).

Some 3-4 teams will call the rotation PRE-SNAP in conjunction with a LB blitz. E.g. SILB blitz, SS down to his hook/curl zone, CBs and FS have deep thirds. This leases you in 4 under, 3 deep, which is sound against two back sets.

You can also play "Robber" out of that look. SS plays the role of the FS in a 4-4 Robber coverage. The FS has weakside flat. Excellent run defense and somewhat deceptive.