luckadjusted
NFL Week 9 · 2026

Week 3 2023 · September 24, 2023

Bears at Chiefs, Week 3 2023: who deserved to win?

The Chiefs beat the Bears 41–10, and the replays back it up: with the way both teams actually played, the Chiefs win 10 of 10.

Before kickoff the Chiefs were 83% favorites.

Final

Chicago Bears 10
Kansas City Chiefs 41

September 24, 2023 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −13

Luck index +1 Chiefs about even · −1 Bears

Each team’s own plays from this game, resampled into new drives 4,000 times: with the way both teams actually played, how often does this performance win? How the replay works

Ten replays. Bears win 0, Chiefs win 10.

  1. 1 CHI 31 KC 34
  2. 2 CHI 24 KC 31
  3. 3 CHI 20 KC 31
  4. 4 CHI 10 KC 24
  5. 5 CHI 16 KC 34
  6. 6 CHI 3 KC 24
  7. 7 CHI 10 KC 33
  8. 8 CHI 10 KC 38
  9. 9 CHI 9 KC 41
  10. 10 CHI 6 KC 45

Three other ways to ask

Each answers a different question, so none of them replaces the replay above.

The closing betting line, turned into a probability. What everyone knew before the game.

The line plus what this game showed, weighted by how much one game can tell. It stays close to the line because one game says little.

Every kick, fumble bounce, drop, conversion and judgment call redrawn; everything else fixed. The narrowest view of luck.

How 4,000 replays ended

Bears win 1% of them, Chiefs 99%. The line is what actually happened: Chiefs by 31.

Show as a table
Final margin in the replaysShare of replays
Bears by 17+0.0%
Bears by 9–160.1%
Bears by 1–80.9%
Level after regulation0.3%
Chiefs by 1–83.0%
Chiefs by 9–1611.1%
Chiefs by 17+84.5%

Where the luck was

What the luck was worth

Every lucky and unlucky play, weighted by the moment it happened: its swing in win probability, added up by kind. A missed kick in a decided game counts for nothing; the same kick at the end of a tie game can be most of a win.

Swings add up across a game, so in one that went back and forth they can pass 100%. On the scoreboard the same luck was worth +13.4 points to the Chiefs: the final margin was Chiefs by 31, without the luck Chiefs by 17.6. Luck shares are the fitted ones (how much of each kind is luck).

The kicks

How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.

  • H. Butker, 41 yds made · 87% expected
  • H. Butker, 38 yds made · 91% expected
  • C. Santos, 21 yds made · 99% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Bears 6 for 32 yards, Chiefs 3 for 15 yards

Every accepted flag, in order, and what it did to the helped team’s chance of winning at that moment, including any play it wiped out (points on the scoreboard in grey). A flag in a decided game is worth nothing; one at the turn of a close game can be worth most of a win. Judgment calls count half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued

WhenFlagWin probability for
Q1 7:37 Unnecessary Roughness on the Bears (Tyrique Stevenson), 1 yard +1% KC +0.5 pts
Q1 7:21 False Start on the Chiefs (Travis Kelce), 5 yards · pre-snap +2% CHI +0.6 pts
Q2 3:05 Delay of Game on the Bears, 5 yards · pre-snap +1% KC +0.4 pts
Q2 0:52 Delay of Game on the Bears, 5 yards · pre-snap 0% KC +0.2 pts
Q2 0:27 Illegal Formation on the Chiefs, 5 yards, wiping out the play · pre-snap 0% CHI +6.2 pts
Q2 0:18 Face Mask on the Bears (Jaylon Jones), 15 yards 0% KC +1.7 pts
Q3 8:54 Face Mask on the Bears (Jaquan Brisker), 1 yard 0% KC +0.5 pts
Q4 10:11 False Start on the Chiefs, 5 yards · pre-snap 0% CHI +0.3 pts
Q4 9:27 Defensive Offside on the Bears (Dominique Robinson), 5 yards · pre-snap 0% KC +0.3 pts

Bears penalties, every game · Chiefs penalties, every game · All teams, 2023

When it happened

Chiefs’ chance of winning

As low as 50% and as high as 100%. Numbers mark the biggest luck moments, listed below.

nflfastR’s in-game win probability. It ignores the betting line, so it starts near even. Shaded above the middle while the Chiefs were ahead in it, below while the Bears were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:22 The Chiefs converted 3rd & 83rd & 4th downs · 37% expected +7% KC KC: Punt
2 Q1 12:39 The Chiefs were stopped on 3rd & 53rd & 4th downs · 47% expected +3% CHI KC: Punt
3 Q1 10:28 The Bears were stopped on 3rd & 43rd & 4th downs · 45% expected +4% KC CHI: Punt
4 Q1 7:21 False Start on the Chiefs (Travis Kelce), 5 yardsPre-snap flags · 23 flags in 4454 snaps before, position avg 1 per 286 +2% CHI CHI: Punt
5 Q1 6:12 The Bears converted 3rd & 33rd & 4th downs · 51% expected +4% CHI CHI: Punt
6 Q1 3:18 The Bears were stopped on 3rd & 63rd & 4th downs · 37% expected +3% KC CHI: Punt
7 Q2 12:25 The Chiefs converted 3rd & 73rd & 4th downs · 40% expected +3% KC KC: Touchdown
8 Q2 3:05 The Bears fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50Delay of Game on the Bears, 5 yardsPre-snap flags +2% KC CHI: Turnover

Missing players

Key players (usually on the field for half the snaps or more) who missed this game or part of it, valued by position and quality. The same players are missing in every replay, so this counts as luck in points only.

  • Nick Bolton (KC LB), out · 0.5 pts
  • Braxton Jones (CHI T), out (IR) · 0.7 pts
  • Kyler Gordon (CHI CB), out (IR) · 0.7 pts
  • Eddie Jackson (CHI FS), out · 0.5 pts
  • Teven Jenkins (CHI T), out (IR) · 0.4 pts

Adjust the assumptions

Disagree with how much of a fumble bounce or a pass interference call is luck? Change it and the coin-flip replay reruns in your browser.

Only coin-flips re-rolled

Bears 0% · Chiefs 100%

Final margin
Chiefs by 31
Luck in points
13.4 for the Chiefs
Luck-adjusted margin
Chiefs by 17.6
Replay with same day's form
Bears 1% · Chiefs 99% unchanged: why
How much of each is luck?

0% treats it as skill, 100% as pure luck. The tick is our fit.

What counts

None by default: our tests measured no carryover after a lucky break. Slide it up to count a break for more than its own swing. Why

Flip a play

Force the other outcome, in this game and in every replay: a made kick becomes a miss, a stop becomes a conversion, a flag goes the other way.

About these numbers

Play-by-play and win probability from nflfastR via nflverse; kicks valued against each kicker’s own record; drops and interception-worthy throws from FTN charting; injuries from snap counts and injury reports.

Methodology and validation · All Week 3 2023 games · Bears · Chiefs

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