The game is similar to the Rams/Seahawks game a couple of weeks ago which was also a division game on a short week with the higher rated team [the Rams] coming off a loss to Jameis and The Bucaneers.
Rams opened -1.5 and moved to +2, probably due to sharp action on the Seahawks similar to this game.
Rams lost by 1 thanks to a missed FG [which screwed the Rams ML bettors like me] after significantly outgaining the Seahawks but kicking 5 FG's. If the Rams had made the chip shot, they would have won outright and covered the open and the closing lines.
I'm betting that there has been an over reaction to the Broncos recent wins against the Chargers and the Titans vs writing off the Chiefs in a division game following a loss to a good team but non division rival.
Summary
1. In a division game, discount the form from the preceding week.
2. Division games count for 2 non division wins.
Often the weaker team performs better than expected in division games and loses but covers, but that looks to be anticipated in this line due to recency bias.
Disclosure:
I've bet 1u on th Chiefs to cover this week
The Rams missed FG against the Seahawks screwed me
I had the Broncos as the last leg of a 5 leg 27x parlay when they lost to Uncle Rico after leading 17-3 with less than a minute to go in Q2, just before Joe Cools interception [I was kicking myself for only hedging 35% at the time]