The one play you cannot live without?

We all have that one play that is either the basis of our game, or the break glass in case of emergency play. What is yours?

Mine is pistol trips, HB zone weak. It's the foundation of my entire game, and I have yet to find a better run play against zone defenses. It's also pretty good against man and blitz, but it murders zone. Everything I do in H2H in CUT is built off and around that one play. It's also a staple of my dynasty playbook, but that one has a lot more diversity in it.