We’re going to take a look at the pro style formations, ie defending 21 personnel. Keeping to the plan we can keep our IMFB 4-2-5 defense in “Miami” against 21 personnel. However, there are many checks we can make depending on what’s hurting us the most.
Typically, we would like to stay in a base Miami Over front. That’s your true 4-3, playing quarters (cover 4 pattern-match) behind it.
This keeps you in your true Miami alignment re DL and LB and the run fits can remain similar to playing 30 personnel.
Here is a simple adjustment to when power and quick 3-step throws in the flat to the TE are starting to hurt your defense. You can call “Jam.” Jam puts the Sam Linebacker on the line of scrimmage in a 7 (outside shoulder of the TE, some call it a 9) and kicks the DE into a 6 (head up on the TE). The Mike and Will move into 20’s (over the G’s). This doesn’t change much to coverage in the back 4, but for the linebackers the Sam goes directly into the flat, and the MLB will play hook-curl, and WLB will play hook-curl-flat.