How to (generally) read coverages pre and post snap.
Cover 2 – Two high safeties, CBs either on line of scrimmage facing in towards ball or 5 yards off line of scrimmage. Flooding one side of field wins for offense.
Cover 2 man – Two high safeties. CBs are pressed to line facing WR. Release, quick cuts and speed win.
Cover 3 – One high Free Safety, CBs are 8 yards off ball facing in towards ball. Flooding one side of field or throwing short win.
Cover 1 man – Very similar look to cover 3. Rarely run online though. Need to read after snap if they mix it in. Quick cuts/speed win.
Cover 4 – 2 deep safeties, CBs 8 yards off ball facing towards ball. Flooding one side of field wins. Also switch routes deep.
Cover 0 – All out blitz, no safety deep. Throw drag/slant, quick pass to fast HB on arrow route.
If they base align, then you have to read the safeties and defense’s movement after the snap. Safeties stay high and CBs low, cover 2. If the DBs follow individual WRs, man. If one safety drops to the box, cover 3. If CBs and Safeties drop, cover 4.