The Kansas City Chiefs offense is good at everything. There is no secret formation, play concept, tendency, etc. that defines their offense by itself. Quarterback Patrick Mahomes can punish defenses over the top just as well as he can pick them apart with a handful of different receivers in between zones. The rushing offense, while not featured as heavily, is plenty effective in its own right, too. It wouldn't be right to boil down Kansas City's passing prowess to just one thing.
Since there is not enough time between now and the Super Bowl to cover everything the Chiefs do on offense, let's hone in on what we can. In fact, let's hone in on what the major part of their offense in most recently.
Against the Tennessee Titans in the Conference Championship round, the Chiefs abused 3x1 formations. The Chiefs operate out of 3x1 on a regular basis already, especially with tight end Travis Kelce flexed out as the isolated receiver, but they pumped up their 3x1 usage even more against the Titans. At least two-thirds of the offense either had the offense initially lining up in 3x1 or snapping the ball in 3x1 after a shift or motion. The Chiefs were living in those formations.
Even much of the Chiefs' running game was out of 3x1 looks. Though they had just 12 non-quarterback runs in the first three quarters of the game, Kansas City found ways to pick up yards on the ground by getting a little creative with their 3x1 formations.
On this play, the Chiefs start in a 4x1 empty set before shifting into a 3x1 under-center formation with a tight bunch to the left. To the offense's right, the open side of the field, is a single wide receiver (Demarcus Robinson, 11) aligned all by himself in a normal split outside the numbers. The gap between the core of the offensive formation and Robinson all by his lonesome creates a natural alley for a wide running play. Rather than pitch it to the running back out there, Kansas City opts for a slower-developing play by giving it to Tyreek Hill (10) on an end-around. Tight end Travis Kelce (87), the innermost player in the bunch, comes across the formation and bends into the alley to become a lead blocker for Hill. With all that space to work with and Kelce leading the way, Hill is able to pick up maybe the easiest 7 yards of his life to set the Chiefs up for a comfortable second-and-short.
Running the ball isn't Kansas City's M.O., however, as evidenced by their mere dozen non-quarterback runs before the fourth quarter. Anyone could tell you that about this team. Picking up yards on the ground is more of a byproduct of the rest of the offense, not a featured function. It's all about throwing the ball and catering the offense to do so. When you have a quarterback like Patrick Mahomes, go right ahead.
In some of Kansas City's 3x1 formations, they will get Hill and Kelce both working from the trips side of the formation. Sometimes Kelce is the No. 3 (innermost receiver), sometimes it's Hill, but regardless of their exact alignment, every defense is scared of trying to pick those two up in coverage when they are releasing from generally the same area. Both players can do massive damage if left open for even a second, and slotting them right next to each other only makes it more difficult to not concede that second.
Of course, when those two are on the same side of the formation, the solo receiver to the opposite side must be put to good use. While the Chiefs have plenty of solid options outside of Kelce and Hill, none of them quite compare, so it's best that the solo receiver becomes more of a conduit for the other two to succeed rather than a receiver who is actually designed to get the ball.
Take the following play, for instance. Kelce is the No. 3 and Hill is just outside of him as the No. 2, while Sammy Watkins (14) stands far outside the numbers as the No. 1. The solo receiver on the other end is tight end Blake Bell, who is in a tight split on the short side of the field. The defense sort of scrunches up to the offensive formation as a response, leaving just about every coverage defender to the offense's left.
At the snap, Hill stutters for a moment to let Kelce get vertical for a couple of steps before cutting under him to cross the field. Bell runs a vertical route from the opposite end to clear out that side of the field for a crossing route. The Titans are in press-man coverage with another player walked up inside of Kelce to help press him before flowing off into a coverage assignment. While Kelce himself is slowed down, the heavy press strategy creates a barrier of bodies between defensive back Adoree Jackson (over Hill) and Hill as he cuts underneath Kelce. With Jackson caught up in traffic, the only defender left in Hill's way is a linebacker trying to wall him off. The linebacker sure tries his darndest, but Hill hits him with a minor jab step down low before clearing over the top of him and sprinting free to the sideline. Mahomes finds Hill running free, as he often does, for a 15-yard pickup. The Chiefs scored two plays later.
Giving either Kelce or Hill free releases, especially in the red zone, can be foolish. It's not hard to see why the Titans would not want either of them running free off the line. In the same vein, over-indexing to stop them off the snap can be boom-or-bust, and it was a bust for the Titans in that instance. Damned if you do, damned if you don't.
Another deadly instance of 3x1 usage from the Chiefs was also in the red zone. Right on the Tennessee 20-yard line, the Chiefs turned the Titans' coverage rules against them to get Hill running free down the painted numbers for an easy touchdown toss.
Mahomes doesn't give the Titans a chance to respond to what the Chiefs want to do on the following play. As the Chiefs come out of the huddle, Hill walks out to be the No. 3 receiver while fellow speedster Mecole Hardman (17) aligns just outside of him as the No. 2, just as Hill and Kelce were aligned in the previous play. However, the moment Hardman gets set on the line, Mahomes motions him inside of Hill, making Hardman the new No. 3. For the particular coverage Tennessee appears to be in, that's a problem.
The second clip gives a better picture of what happens next. Titans safety Kenny Vaccaro (24) puts his eyes on the No. 3 as soon as the ball is snapped and slides across the field to cover the over route. It's tough to say with certainty that the Titans had this safety technique assigned with Hill being the No. 3 in mind, but they wouldn't be the first team to do it, and it makes sense given how devastating Hill can be when left to sprint across the field in one-on-one coverage. Vaccaro's intention is also too instant and deliberate for this not to have been his direct assignment. With the motion and snap happening so fast, Tennessee has no time to check out of the coverage, leaving Hill all by himself against Logan Ryan (26) down the seam. The obvious party wins the rep and the Chiefs find their second touchdown of the day.
There is no telling exactly how much 3x1 the Chiefs will turn to versus the 49ers. It's going to be a key part of their arsenal regardless, but it's tough to say whether they will relentlessly play out of those looks the way they did against the Titans. The volume at which the Chiefs beat Tennessee over the head with 3x1 looks was embarrassing by the end of the match, in all honesty. This year's 49ers defense is not likely to look that helpless.
That being said, throwing a non-Hill or non-Kelce player out as the solo receiver to cornerback Richard Sherman's side while three receivers slice-and-dice the 49ers secondary on the other side could be something we see the Chiefs try a fair bit. Sherman doesn't like to travel much, and Andy Reid isn't foolish enough to try beating Sherman with brute force, especially considering the year he is having.