Playbooks

Strong I Slot takes the base Strong I two back look and slides one receiver into the slot, giving you a 21 personnel package that still threatens downhill runs while creating a legitimate three level passing structure. Instead of the balanced split end alignment you get in Strong I Normal or Strong I Close, the slot receiver aligns inside the numbers with a free release, which means he is almost always covered by a nickel defender, a linebacker, or a safety rolling down. That is the entire point of the set: you are forcing the defense to declare whether they want to keep base personnel on the field against 21 and accept a mismatch inside, or substitute lighter and take on Counter Weak, HB Power O, and Inside Zone Split with a smaller box.
The alignment gives you a fullback and a halfback in the backfield with a tight end attached to the strong side, so the run game is fully intact. HB Toss, HB Stretch, HB Power O, HB Dive, and Inside Zone Wk all run out of the same shell, and the play action off those looks is the real weapon. PA Post Shot, PA Power O, PA Boot Slide, and PA Lead Draw Shot all sell the same downhill action that your run plays establish, and because the defense sees two backs and a tight end, second level defenders bite hard on the fake before the slot receiver clears into the intermediate window.
Where this set separates itself is the passing concept variety hiding inside a heavy personnel group. Dagger and Mills both give you high low reads on the middle of the field safety with the slot running the clearing route, which is exactly how you attack Cover 3 and single high man. China Special and Double Slant give you quick game man beaters with a rub element built into the slot alignment, and Curl Flat handles zone. Add Bubble Screen, HB Slip Screen, and HB Stretch Alert Bubble (the Gadget tag on this set is earned) and you have constraint plays that punish overpursuit and heavy user blitzing from a formation the defense has already labeled as a run formation.
Establish HB Power O, Inside Zone Split, and HB Stretch early so the linebackers commit downhill, then go to PA Post Shot and PA Lead Draw Shot on the same down and distance to punish the run fit.
Motion the slot receiver across the formation pre snap to diagnose coverage: if a defender travels with him you have man and you should get to Double Slant or China Special, if the defense stays put you are in zone and Curl Flat or Mills is your call.
On third and medium against single high, run Dagger and read the safety, hitting the dig behind the vacated hook window when the post clears the top.
Hot route the slot to a corner route when you identify a linebacker matched on him, which is the highest percentage isolation this set offers against base personnel.
Use Bubble Screen and HB Stretch Alert Bubble as your answer to heavy box counts and edge blitzing, and pair HB Slip Screen with your interior run calls to slow down aggressive user defenders in the middle.
Against Cover 2, work Mills and let the slot attack the seam between the corner and the half field safety instead of forcing the outside route.