Vahe Gregorian: KC Chiefs’ collapse not end of era, but it reminds us the window won’t be open forever

Before their stupefying collapse on Sunday at Arrowhead Stadium, an era-defining moment was in the Chiefs’ grasp.

Just waiting to be seized, even.

Playing in their NFL-record fourth straight home conference championship game, they had swamped Cincinnati 21-3 in the first half and were on the verge of becoming just the fourth franchise to play in three (or more) straight Super Bowls.