Playbooks

Nickel 2-4 Odd is a defensive set, so everything here is about how you defend rather than how you attack. The alignment puts two down linemen on the field with four linebackers standing up and five defensive backs behind them, which is the key difference from more traditional Nickel sets like 3-3 Cube or Nickel Normal that keep three or more hands in the dirt. Because two of your four linebackers are walked up on the edges in that "odd" spacing, the offense cannot tell pre-snap who is rushing and who is dropping. That ambiguity is the entire value proposition of the set.
Compared to other Nickel sets, 2-4 Odd trades run-fit integrity for coverage disguise and rush flexibility. The tags on this set (RLE, RRE, SUBLB, SLCB) mean you are subbing linebackers and edge players into spots where speed matters more than size, so this is where you put your best pass rushing linebackers and your fastest hybrid safety at the slot corner spot. The five defensive backs let you match empty and 2x2 spread looks without burning a timeout, and the four linebackers give you enough zone droppers to fill hook and curl windows even when you only rush two.
The playbook here is deep and balanced: Cover 3 Sky, Cover 3 Cloud, Cover 4 Drop, Cover 6, Tampa 2, Pinch 2, and Cover 2 Man cover the shell spectrum, while Cover 1 Robber Press, Sam Mike 1, Sam Mike 3 Press, 3 Buzz Sting Press, Bench Blitz 3, LB Cross 3 Show 2, 3 Seam Show 2, and Pinch 0 give you pressure and disguise. The Show 2 concepts are the money plays because they present a two high shell pre-snap and rotate post snap, which is exactly what you need against opponents who read your safeties before deciding to attack the seam or the sideline.
Call this set on second and long or third and medium when you expect a spread passing look, then rotate between Show 2 concepts and Cover 3 Cloud so the offense never gets the same post snap picture twice.
Use the SUBLB and SLCB tags to get your fastest pass rushing linebacker on the field and your best coverage hybrid at the slot, since this set lives on speed rather than size.
Pair 3 Buzz Sting Press with a user-controlled deep safety and manually take away the deep middle, letting the buzz defender handle the shallow crosser underneath.
Do not sit in Pinch 0 on early downs. Save it for third and long or a two-minute situation where the offense has to hold the ball, and make sure you shade coverage over the top first.
If the opponent checks into a heavy run set after seeing 2-4 Odd, audible out to a base Nickel or 3-4 look rather than trying to hold the edge with two down linemen.