In these chaotic times, there is great comfort in the familiar, and the most familiar scene in the last four N.F.L. postseasons has been an A.F.C. championship game staged at Arrowhead Stadium, home of quarterback Patrick Mahomes and the Kansas City Chiefs.
His presence in this round feels inevitable. The absence of some others feels disorienting.
On Sunday, for the first time in 12 seasons, none of the triumvirate of Tom Brady, Aaron Rodgers and Ben Roethlisberger will be playing for a conference title, their Super Bowl hopes — and splendid careers, perhaps — expiring earlier these playoffs.