luckadjusted
NFL Week 9 · 2026

Week 2 2021 · September 20, 2021

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

Lions at Packers, Week 2 2021: who deserved to win?

The Packers beat the Lions 35–17, and the replays back it up: with the way both teams actually played, the Packers win 9 of 10.

Before kickoff the Packers were 80% favorites. The biggest swing (Q3, 5:57 left): the Lions were stopped on 4th & 1, worth 14 points of win probability to the Packers.

Final

Detroit Lions 17
Green Bay Packers 35

September 20, 2021 · Lambeau Field · Closing line: Packers −11.5

Luck index +8 Packers about even · −8 Lions

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. Lions win 1, Packers win 9.

  1. 1 DET 23 GB 17
  2. 2 DET 24 GB 27
  3. 3 DET 9 GB 14
  4. 4 DET 27 GB 34
  5. 5 DET 24 GB 35
  6. 6 DET 17 GB 31
  7. 7 DET 27 GB 44
  8. 8 DET 6 GB 28
  9. 9 DET 13 GB 38
  10. 10 DET 6 GB 38

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

Lions win 8% of them, Packers 92%, counting the 2% still level after regulation as half each. The line is what actually happened: Packers by 18.

Show as a table
Final margin in the replaysShare of replays
Lions by 17+0.5%
Lions by 9–162.0%
Lions by 1–85.3%
Level after regulation1.6%
Packers by 1–816.9%
Packers by 9–1622.1%
Packers by 17+51.7%

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 +4.6 points to the Packers: the final margin was Packers by 18, without the luck Packers by 13.4. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Lions 9 for 78 yards, Packers 5 for 50 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 8:10 Illegal Use of Hands on the Lions (Amani Oruwariye), 5 yards +3% GB +0.9 pts
Q1 7:02 False Start on the Packers (AJ Dillon), 5 yards · pre-snap +1% DET +0.8 pts
Q1 0:56 False Start on the Lions (T.J. Hockenson), 5 yards · pre-snap +3% GB +0.5 pts
Q1 0:35 Offensive Holding on the Lions, 10 yards +3% GB +1.1 pts
Q2 14:16 Intentional Grounding on the Lions (Jared Goff), 14 yards +4% GB +1.0 pts
Q2 14:12 False Start on the Lions, 5 yards · pre-snap +2% DET +0.1 pts
Q2 10:32 Face Mask on the Packers (De'Vondre Campbell), 15 yards +6% DET +1.8 pts
Q3 15:00 Offensive Holding on the Packers (AJ Dillon), 10 yards +1% DET +0.9 pts
Q3 4:57 Offensive Holding on the Packers, 10 yards, wiping out the play +6% DET +1.6 pts
Q3 4:27 Defensive Pass Interference on the Lions, 25 yards +5% GB +1.8 pts
Q3 1:46 Offensive Holding on the Packers, 10 yards +3% DET +1.3 pts
Q3 1:24 Defensive Holding on the Lions (Alex Anzalone), 5 yards +2% GB +0.8 pts
Q4 12:48 Defensive Pass Interference on the Lions (Amani Oruwariye), 4 yards +2% GB +2.1 pts
Q4 10:29 Delay of Game on the Lions, 5 yards · pre-snap 0% GB +0.6 pts

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

When it happened

Packers’ chance of winning

As low as 37% 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 Packers were ahead in it, below while the Lions were.
#WhenWhat happenedWin probability forNext drive
1 Q2 14:16 The Lions were stopped on 3rd & 93rd & 4th downs · 32% expectedIntentional Grounding on the Lions (Jared Goff), 14 yardsJudgment calls · 5 flags in 2341 snaps before, position avg 1 per 711 +8% GB DET: Punt
2 Q2 10:32 Face Mask on the Packers (De'Vondre Campbell), 15 yardsJudgment calls · 2 flags in 2008 snaps before, position avg 1 per 409 +6% DET DET: Touchdown
3 Q3 12:20 The Packers converted 3rd & 123rd & 4th downs · 28% expected +10% GB GB: Touchdown
4 Q3 10:30 The Packers converted 3rd & 63rd & 4th downs · 42% expected +7% GB GB: Touchdown
5 Q3 5:57 The Lions were stopped on 4th & 13rd & 4th downs · 76% expected +14% GB DET: Turnover
6 Q3 5:26 The Packers converted 3rd & 143rd & 4th downs · 26% expected +7% GB GB: Touchdown
7 Q3 4:57 Offensive Holding on the Packers, 10 yards, wiping out the playJudgment calls +6% DET DET: Turnover
8 Q3 3:58 The Packers converted 3rd & 73rd & 4th downs · 39% expected +7% 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.

  • David Bakhtiari (GB T), out (IR) · 1.4 pts
  • Za'Darius Smith (GB LB), out (IR) · 0.4 pts
  • Lucas Patrick (GB G), out · 0.3 pts
  • Taylor Decker (DET T), out (IR) · 1.1 pts
  • Tyrell Crosby (DET OL), out (IR) · 0.4 pts
  • Jeff Okudah (DET CB), out (IR) · 0.2 pts
  • Kevin Strong (DET DT), out · 0.2 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

Lions 0% · Packers 100%

Final margin
Packers by 18
Luck in points
4.6 for the Packers
Luck-adjusted margin
Packers by 13.4
Replay with same day's form
Lions 8% · Packers 92% 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 (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 2 2021 games · Lions · Packers

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