They say a picture is worth a thousand words. So let's start off with a picture. But first, I need you to go ahead and get yourself into the proper mindset.
Imagine yourself as a defensive coordinator in the NFL. Congratulations, you've made it to the big time! Even better for you, you're team is playing a Chiefs squad that has struggled to manufacture points so far in this young season (well, for the most part). Should be a piece of cake, no?
Now imagine you see the Chiefs line up like this:
Hmmm. Things just got interesting in your defensive coordinator world. The Chiefs now have now overloaded the left side of your defense with what looks to be 5,796 tight ends. Who are these guys? Well, from left to right, here's what your scouting reports tell you...
You've got far and away the most tape on veteran Anthony Fasano, the tight end who is immediately next to right tackle Ryan Harris (soon to be Donald Stephenson, to the relief of Chiefs fans worried about the health of Alex Smith).
Fasano is the definition of a "decent" NFL tight end. He's a jack of all trades, master of none type. While you're not scared of him necessarily as a deep threat or "explosive" player, he's a guy who knows how to find open zones and exploit them for first downs. He's also a solid run blocker who is more than capable of taking on linebackers and even the occasional defensive lineman and moving them aside for a runner.
Basically, he's a guy you have to account for, who has caught eight of the 12 passes thrown his way, with seven of them going for first downs. In other words, when teams have ignored Fasano he's made them pay by helping move the chains. He'll also occasionally make catches like this one (seriously, holy crap). He could be going out for a pass, providing additional pass protection, or playing the role of road grater in the run game. You can't be sure until the ball is snapped.
Right next to Fasano is a second-year player named Demetrius Harris. You don't know much about Harris outside of his "vitals." He's a college basketball player who, from what you remember your scouts telling you after preseason, was nowhere NEAR ready to be on the field. Yet here he is, having taken no snaps in Week 1, three snaps in Week 2, and 13 snaps in Week 3.
The real problem with Harris are those aforementioned vitals. He's listed at an unbelievable 6'7, and word is he now weighs in at around 255 pounds or so. In other words, he's no longer a bean pole like he was his rookie year (or a basketball player wearing pads). Additionally, the guy ran a 4.52 40-yard dash in his workouts. Even though you haven't seen much of him, those numbers are enough to make you at least account for him on the field.
The real problem you're having as a defensive coordinator is Harris's tape from the Chiefs most recent game (a convincing win over the Miami Dolphins). Even though Harris is supposed to be some kind of wannabe Jimmy Graham, he played almost exclusively on the line and was run blocking 10 of his 13 snaps on the field. What's worse for you as a coordinator is that he did a heck of a job at it.
"We thought we could get a decent match there with them," Andy Reid said Monday. "You look at Harris and the improvement, I mean you look at the improvement that he's made and those physical blocks that he made in that game. That was pretty impressive."
Suddenly the one-dimensional non-threat is a guy who, like Fasano, could be blocking or going out for a pass. Again, there's no way of knowing until the ball is snapped.
You don't have time to worry about that right now, though. Because the guy to the right of Harris is a problem too. A gigantic problem. Travis Kelce, who through three games is the Chiefs leading receiver (despite playing a shade under half the offensive snaps), is the man on the outside of the formation.
Kelce is a nightmare. At 6'5 and 260 pounds, he's as physically imposing as almost any tight end in the league. The problem is he runs like a deer. You know, if the deer were hopped up on crystal meth and looking to crack people over the head. Kelce is way too fast for any linebacker and way to big and strong for any secondary player. As a former quarterback, he's also not "just" an athlete. he runs decent routes and knows how to get open.
Of course, Kelce isn't just a receiver. His run blocking can be described as "vicious." Even though he has some technique to clean up, he hits (not blocks. Hits) until the whistle and is highly aggressive. He has more balance than Jimmy Graham (who, despite being a great receiver, is a shadow of a run blocker). He's basically a clone of The Gronk, but one who is currently healthy.
(Crosses fingers, knocks on wood, sacrifices a virgin at midnight)
You're a defensive coordinator, and you've heard all about how Andy Reid doesn't run double tight end formations. Except all that handy information isn't helping you because not only is he coming at you with two tight ends on the majority of his plays, he's coming at you with THREE tight ends on the formation.
What do you do? If you stack the box you're running a huge risk of Kelce getting behind your defense, or Jamaal Charles (or Knile Davis, Or Joe McKnight, or De'Anthony Thomas If He's Healthy... what a stacked backfield. Seriously) burning some poor unfortunate linebacker left in man coverage out of the backfield. It's quite the risk to take, because any of those guys getting to the open field is a risk to gain huge yardage.
Additionally, even though he isn't Megatron out there, Dwayne Bowe isn't a guy you're entirely comfortable leaving completely alone in man coverage with no help. And stacking the box will almost certainly leave him with that sort of matchup.
Of course, it's almost out of the question to NOT play with eight or nine men in the box against this kind of formation. You've got eight guys up front blocking, with a very dangerous back behind them. It's a simple matter of numbers. You can't afford to let your defense get run over by a heavy formation. Having the opposing team run the ball down your throat always has been and always will be a near-certain way to lose football games.
Oh, crap, they're about to snap the ball. Last week, in an effort to mess with you, the Chiefs passed out of all their heavy formations. Are they running or passing this week? You have absolutely no idea. And neither do your players. This isn't how this game was supposed to go. The Chiefs are supposed to be predictable!
All you can do is grit your teeth, hope for the best, and curse Andy Reid for having the stones to change his approach to the game after all these years.