luckadjusted

Week 6 2021 · October 17, 2021

No FTN charting for this game (drops and interception-worthy throws are not modelled).

Packers at Bears, Week 6 2021: who deserved to win?

The Packers beat the Bears 24–14, and it was no fluke: replayed with the way both teams actually played, the Packers win 9 of 10. The Bears had the bounces: fumble bounces alone were worth 1.6 points to the Bears.

Before kickoff the Packers were 66% favorites. The biggest swing (Q4, 10:57 left): Offensive Holding on the Bears, 10 yards, wiping out the play, worth 16 points of win probability to the Packers.

Final

Green Bay Packers 24
Chicago Bears 14

October 17, 2021 · Soldier Field · Closing line: Packers −5.5

Luck index +10 Packers about even · −10 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. Packers win 9, Bears win 1.

  1. 1 GB 29 CHI 0
  2. 2 GB 31 CHI 7
  3. 3 GB 27 CHI 7
  4. 4 GB 24 CHI 7
  5. 5 GB 26 CHI 14
  6. 6 GB 23 CHI 13
  7. 7 GB 17 CHI 10
  8. 8 GB 17 CHI 13
  9. 9 GB 19 CHI 17
  10. 10 GB 21 CHI 28

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

Packers win 90% of them, Bears 10%, counting the 2% still level after regulation as half each. The line is what actually happened: Packers by 10.

Show as a table
Final margin in the replaysShare of replays
Packers by 17+49.5%
Packers by 9–1622.9%
Packers by 1–816.9%
Level after regulation1.7%
Bears by 1–86.3%
Bears by 9–161.9%
Bears by 17+0.8%

Where the luck was

Take the luck out

The final margin was Packers by 10. Remove the luck, one kind at a time, and it becomes Packers by 10.9.

Each row takes one kind of luck out of the margin. Color shows which team it helped. Luck shares are the fitted ones (how much of each component is luck).

When it happened

Bears’ chance of winning

As low as 0% and as high as 83%. 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 Bears were ahead in it, below while the Packers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 12:10 The Packers were stopped on 3rd & 103rd & 4th downs · 32% expected +11% CHI GB: Punt
2 Q1 8:09 The Bears converted 3rd & 33rd & 4th downs · 50% expected +9% CHI CHI: Touchdown
3 Q2 10:02 The Packers converted 3rd & 13rd & 4th downs · 71% expected +5% GB GB: Touchdown
4 Q2 5:00 Offensive Pass Interference on the Packers (Equanimeous St. Brown), 10 yards, wiping out the playJudgment calls · 1 flag in 348 snaps before, position avg 1 per 399 +14% CHI CHI: Punt
5 Q2 0:25 The Bears were stopped on 3rd & 133rd & 4th downs · 22% expectedDelay of Game on the Bears, 5 yardsPre-snap flags +8% GB CHI: Punt
6 Q3 13:48 The Bears were stopped on 3rd & 63rd & 4th downs · 36% expected +5% GB CHI: Punt
7 Q4 13:41 The Bears converted 3rd & 33rd & 4th downs · 50% expected +5% CHI CHI: Touchdown
8 Q4 10:57 Offensive Holding on the Bears, 10 yards, wiping out the playJudgment calls +16% GB GB: Touchdown

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.

  • Germain Ifedi (CHI T), out (IR) · 0.8 pts
  • Germain Ifedi (CHI OL), out (IR) · 0.5 pts
  • David Montgomery (CHI RB), out (IR) · 0.5 pts
  • Duke Shelley (CHI CB), out · 0.3 pts
  • Duke Shelley (CHI DB), out · 0.2 pts
  • Jaire Alexander (GB CB), out (IR) · 0.9 pts
  • Marquez Valdes-Scantling (GB WR), out (IR) · 0.5 pts
  • Kevin King (GB CB), out · 0.4 pts
  • Za'Darius Smith (GB LB), 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

Packers 93% · Bears 7%

Final margin
Packers by 10
Luck in points
0.9 for the Bears
Luck-adjusted margin
Packers by 10.9
Replay with same day's form
Packers 90% · Bears 10% unchanged: why
How much of each is luck?

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

What counts

We tested momentum on 19,000 lucky breaks and found none, so it's off by default. 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 (not available for this game); injuries from snap counts and injury reports. No FTN charting for this game (drops and interception-worthy throws are not modelled).

Methodology and validation · All Week 6 2021 games · Packers · Bears

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