Bears earned the win over Tampa Bay on a day the offense lost ground
The snaps gave Chicago an 85% chance and a 5.7-point edge, even with an offense that lost ground on average and a 27-24 final.

OffenseThe verdict
Played like that, the Bears win 85% of the time. The snaps said Bears by 5.7 points, and the scoreboard said 27-24, a margin of 3. This was an earned win.
It was not a pretty one. The Chicago offense posted an EPA per snap of -0.19. EPA, expected points added, tracks how much each play moves the scoring outlook, so a negative number means the offense lost ground on the average snap. Tampa Bay was worse at -0.27. The Bears won by being less bad over sixty minutes.
What the score hid
The success rate tells the same story in a narrow range: Chicago 43%, Tampa Bay 40%. Neither team moved the ball with any consistency.
Luck points ran against the home side. The Bears finished at -2.4 and the Buccaneers at +1.6, a gap of 4.0 points in Tampa Bay's favor. The real margin was smaller than the deserved one because of that gap.
The swing play came in the third quarter with 3:50 on the clock. B.Mayfield threw short right for C.Otton, defender J.Johnson stepped in front at the Chicago 33 and ran it back 67 yards for a touchdown. That one play moved win probability by 28 percentage points. It was a defensive score, and it is why an offense at -0.19 per snap still put up 27.
The calls
The Bears graded five fourth downs. Three matched the model or cost nothing. Two did not.
In the second quarter, at 3:06, Chicago faced fourth-and-4 from the Tampa Bay 7 with an 89% win probability and kicked a field goal. The model leaned toward going and put the cost at 0.4 expected points. The kick was good, but it was still the call to question. In the third quarter at 10:40, Chicago punted on fourth-and-3 from its own 27. The model called that a tossup and put the cost at 0.2.
The flags cut both ways. The heaviest was a Chicago offensive holding in the third quarter at 7:26, nine yards and 6 points of win probability. Tampa Bay gave back 4 points at 6:52 with its own holding call, ten yards. A Chicago face mask at 7:19 of the fourth quarter cost 15 yards and 4 points, and it came late. A kickoff short of the landing zone in the first quarter added 3.
Ben Johnson comes out of this fairly. He has zero clear fourth-down misses on the season and went on 9 of 14 chances where the model said go. His Chicken Index is 36%, 22nd of 32 on the most-timid-first scale. The field goal at the 7 is the kind of call that keeps that number from falling.
The trend
Chicago is 7-2 with 6.8 deserved wins, a luck figure of 0.2 wins that ranks 14th of 32 on the luckiest-first list. The record is honest. The Bears have no games robbed and no games won while lucky, and they are 3-1 in one-score games.
Total luck points sit at -2.1. Fumble recovery luck is -2.6, while opponent kicking luck is +4.9. The fumble number is the one most likely to drift back toward zero.
The flag sheet is the real drag. Chicago has 72 penalties for 570 yards, a net of -30 percentage points of win probability. That figure sits beside a net EPA per snap of 0.102, seventh of 32.
The next game is week 11 against the New Orleans Saints at home, Sunday, Nov. 22, 1:00 PM ET, on Fox.