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.

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 34 CHI 10
  3. 3 GB 23 CHI 3
  4. 4 GB 34 CHI 17
  5. 5 GB 33 CHI 21
  6. 6 GB 24 CHI 14
  7. 7 GB 17 CHI 10
  8. 8 GB 35 CHI 31
  9. 9 GB 26 CHI 24
  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

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 +0.9 points to the Bears: the final margin was Packers by 10, without the luck Packers by 10.9. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Packers 3 for 51 yards, Bears 7 for 54 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 toward luck, pre-snap fouls mostly don’t. How calls are valued

WhenFlagWin probability for
Q1 14:54 Neutral Zone Infraction on the Bears (Robert Quinn), 5 yards · pre-snap 0% GB +0.7 pts
Q1 7:32 Defensive Pass Interference on the Packers (Isaac Yiadom), 26 yards +3% CHI +2.3 pts
Q1 4:43 Illegal Block Above the Waist on the Bears (Marqui Christian), 10 yards +1% GB +1.2 pts
Q1 1:13 Unsportsmanlike Conduct on the Bears (Mario Edwards), 15 yards +4% GB +1.6 pts
Q2 5:00 Offensive Pass Interference on the Packers (Equanimeous St. Brown), 10 yards, wiping out the play +14% CHI +4.5 pts
Q2 0:25 Delay of Game on the Bears, 5 yards · pre-snap +1% GB +0.6 pts
Q3 10:01 Defensive Pass Interference on the Bears (Jaylon Johnson), 4 yards +3% GB +1.3 pts
Q4 10:57 Offensive Holding on the Bears, 10 yards, wiping out the play +16% GB +3.3 pts
Q4 4:30 Unnecessary Roughness on the Packers (Kylin Hill), 15 yards +1% CHI +1.4 pts
Q4 4:09 Ineligible Downfield Pass on the Bears, 5 yards, wiping out the play +5% GB +1.4 pts

Packers penalties, every game · Bears penalties, every game · All teams, 2021

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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