In my eyes it had to be this play for the breakdown. It's just rare to see a game won on a "gimmick" play and I will always choose to highlight that when it happens. Is it a sustainable way to win games over the course of the season? No. Is it totally legal and does every team Clemson plays have to waste valuable practice time preparing for it? Yes. Louisville played a great game and is going to absolutely ruin someone's weekend eventually, I'm very grateful it wasn't us dragged down in a Thursday night #GoACC dog fight. All images shown are via the ACC Digital Network.
Clemson is aligned in empty formation, meaning there is no back in the backfield. This is a good tactic to create space in the almost red zone, where the lack of vertical distance to go begins to play in the defenses favor. However if you look closely you will notice this is not a normal empty formation. Two of the three receivers to the right are on the line of scrimmage, rendering the innermost "receiver" ineligible. I put "receiver" in air quotes because that is actually Mitch Hyatt, who, bless his heart, is doing his best approximation of a WR's stance. The nickel back is actually aligned over him. What this means is that player aligned where the left tackle is is an eligible receiver, in this case Jordan Leggett. The Patriots did something sort of like this last year. I swear it's legal. For Louisville's part the defensive backs are all playing well off the line of scrimmage, respecting the threat that Clemson's receivers pose vertically.
The nickel has stopped paying attention to Hyatt, as has everyone else, as he backs up for what could still theoretically be a screen pass. In the future ScElliot could get Hyatt into Peisman consideration by getting him the ball on the edge via a screen if they think he's athletic enough since no one respected him as a threat here. Note that Watson rolled slightly to the right, to compensate for the fact that he will not have the protection a left tackle normally affords. Louisville's left inside linebacker seems to be the only player on the defense even possibly aware Leggett has released into a route, everyone else is worried about the vertical stems of the receivers. This ensures that there will be someone for each of the four DB's to have to watch deep, this means a linebacker has to pickup Leggett and run with him deep, and that's after realizing that Leggett is a threat. Giving up that much time is hard, Leggett is three yards downfield and his counterpart is flat footed (and probably uttering several expletives).
No one was in any position to even contest the ball thrown to Leggett, with both safeties busy with a slot receiver and the linebacker just caught on a play designed to make him look silly. Watson having veins of ice helps a lot, as he very likely could have had a free rusher in his face from his blindside. Louisville stunting their defensive end inside actually helped the protection out a lot, as the defensive tackle playing contain on the Tex stunt was not going to be able to redirect and get to Watson in time. While this play won't always work as well, particularly now that we have shown it, it does force every defensive coach Clemson faces to waste time during his precious twenty hours a week of practice going over it. If ScElliot had it in the toolbox as in "in case of emergency break glass" sort of play I don't think many of us would have argued against them breaking it out on Thursday.