You don’t need to be an expert to know that the loss of Travis Kelce was a significant blow to the Chiefs offense in Week 1. It was particularly a factor on 3rd down, where K.C. went 0-for-7 in the second half.
One of the ways Andy Reid likes to utilize Kelce in these situations is with 1x3 formations where the Chiefs have three receivers to one side and Kelce isolated to the other. This puts the defense in a bind in that they have to make a choice between giving extra attention to Kelce and handling those 3-receiver sets.
With Kelce absent, the Lions were more than content to leave his replacement, Noah Gray, in 1-on-1 coverage and push the rest of the defense to the 3-receiver side. That made Patrick Mahomes’ job finding open receivers a bit more difficult.
You could see it on Kansas City’s first drive of the game. Notice the formation on this 3rd-and-5:
The Lions would play quarters coverage with the back side locked up in man. That meant cornerback Jerry Jacobs on Gray, and linebacker Alex Anzalone on running back Isiah Pacheco:
Weakside safety Kerby Joseph would turn his attention to the 3-receiver side at the snap: