2. Make Justin Fields sit in the pocket (and not throw deep)
Justin Fields is not a good NFL quarterback, but one of the few things he does well is run. Fields is one of the best (if not the best) running quarterbacks in the league. If he gets loose, he's difficult to bring down.
One interesting note is that he's been Jekyll and Hyde when under pressure. In 2022 (and so far in 2023), he's been one of the worst quarterbacks in the NFL at preventing sacks when under pressure. On the other hand, he's excellent at scrambling in the times he does escape the pressure. In my opinion, Fields is a better runner when he escapes a collapsed pocket rather than a clean one. One reason for this could be there are fewer defenders past the LOS when he's under pressure.
One key here is to keep him in the pocket, even if he's not under pressure. Fields getting loose consistently could be a game-changer. Purely as a passer, his passer rating is pretty similar when kept clean and under pressure (72.6 and 67.1, respectively), although his quality of play is significantly worse when under pressure.
Although Fields is a below-average passer overall, he has been excellent on deep throws so far this year. Even though deep attempts only make up 9.1% of his overall throws, he's 5 for 6 for 118 yards, two touchdowns, and a 158.3 passer rating on those plays. On the other hand, Fields is an abysmal 0-6 with two interceptions and a 0.0 passer rating on throws of an intermediate depth (10-19) past the LOS. According to Pro Football Focus ($), 71.2% of his pass attempts are within 10 yards of the LOS (for reference, Mahomes is at 66.3%).
Fields also has a tendency to hold the ball for a long time. According to PFF ($), he has the 3rd highest (out of 33 quarterbacks) time to throw at an average of 3.18 seconds. His passer rating ranks 24th out of 33 QBs on throws that are longer than 2.5 seconds after the snap.
In conclusion, although Justin Fields is a talented player, he hasn't been good so far in the NFL. If Steve Spagnuolo can contain him as a runner, the Chiefs will be in a great position. If he's able to run free, all bets are off. Even though Nick Bolton is out for this game, and Willie Gay is questionable, Kansas City should still be able to corral an offense that is in complete disarray.
3. Keep Patrick Mahomes clean
Another straightforward one. Fresh off an adjusted contract, the Chiefs need to keep Patrick Mahomes clean. Since 2022, Mahomes has a 116.4 passer rating when kept clean, compared to 77.9 when under pressure.
The Bears don't have a strong overall pass rush, although defensive tackle Andrew Billings has been elite through two weeks, but every other defensive lineman has been pretty much a non-factor. Given how good the Chiefs' offensive line is, especially the interior, I don't expect this to be a problem.