luckadjusted
NFL Week 9 · 2026

Week 11 2021 · November 21, 2021

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

Cardinals at Seahawks, Week 11 2021: who deserved to win?

The Cardinals beat the Seahawks 23–13, and the replays lean their way: with the same day's form, they win 6 of 10. The Seahawks had the bounces: injuries alone were worth 18 points of win probability to the Seahawks.

Before kickoff the Seahawks were 57% favorites. The biggest swing (Q2, 0:03 left): M. Prater missed a 39-yard field goal, worth 11 points of win probability to the Seahawks.

Final

Arizona Cardinals 23
Seattle Seahawks 13

November 21, 2021 · Lumen Field · Closing line: Seahawks −2.5

Luck index +36 Cardinals lucky · −36 Seahawks

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. Cardinals win 6, Seahawks win 4.

  1. 1 ARI 25 SEA 3
  2. 2 ARI 23 SEA 7
  3. 3 ARI 17 SEA 6
  4. 4 ARI 21 SEA 13
  5. 5 ARI 22 SEA 17
  6. 6 ARI 16 SEA 14
  7. 7 ARI 21 SEA 24
  8. 8 ARI 13 SEA 20
  9. 9 ARI 7 SEA 20
  10. 10 ARI 7 SEA 30

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

Cardinals win 64% of them, Seahawks 36%, counting the 2% still level after regulation as half each. The line is what actually happened: Cardinals by 10.

Show as a table
Final margin in the replaysShare of replays
Cardinals by 17+17.5%
Cardinals by 9–1620.1%
Cardinals by 1–825.5%
Level after regulation1.7%
Seahawks by 1–818.3%
Seahawks by 9–1611.1%
Seahawks by 17+5.9%

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 +7.6 points to the Seahawks: the final margin was Cardinals by 10, without the luck Cardinals 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.

  • J. Myers, 27 yds made · 98% expected
  • J. Myers, 27 yds made · 98% expected
  • M. Prater, 39 yds missed · 90% expected
  • M. Prater, 53 yds made · 68% expected
  • M. Prater, 36 yds missed · 93% expected
  • Extra point missed · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Cardinals 3 for 32 yards, Seahawks 2 for 17 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 3:28 Defensive Pass Interference on the Seahawks (Tre Brown), 14 yards +6% ARI +2.7 pts
Q2 8:23 Offensive Holding on the Cardinals, 8 yards +2% SEA +0.7 pts
Q2 1:39 Unnecessary Roughness on the Cardinals, 14 yards +4% SEA +1.7 pts
Q3 6:41 Offensive Holding on the Cardinals, 10 yards, wiping out the play +5% SEA +1.4 pts
Q4 2:27 Defensive Pass Interference on the Seahawks (Jamal Adams), 3 yards +5% ARI +1.6 pts

Cardinals penalties, every game · Seahawks penalties, every game · All teams, 2021

When it happened

Seahawks’ chance of winning

As low as 0% and as high as 58%. 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 Seahawks were ahead in it, below while the Cardinals were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:44 The Seahawks fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +6% SEA SEA: Punt
2 Q1 8:35 The Cardinals converted 3rd & 33rd & 4th downs · 55% expected +6% ARI ARI: Touchdown
3 Q1 7:51 The Cardinals fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +5% ARI ARI: Touchdown
4 Q1 6:28 The Cardinals converted 3rd & 103rd & 4th downs · 30% expected +8% ARI ARI: Touchdown
5 Q1 3:28 Defensive Pass Interference on the Seahawks (Tre Brown), 14 yardsJudgment calls · 0 flags in 243 snaps before, position avg 1 per 239 +6% ARI ARI: Touchdown
6 Q2 0:03 M. Prater missed a 39-yard field goalKicks · 90% expected for him +11% SEA ARI: Field goal
7 Q4 4:14 The Cardinals converted 3rd & 73rd & 4th downs · 37% expected +7% ARI ARI: Touchdown
8 Q4 2:27 Defensive Pass Interference on the Seahawks (Jamal Adams), 3 yardsJudgment calls · 9 flags in 2558 snaps before, position avg 1 per 420 +5% ARI ARI: 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.

  • D.J. Reed (SEA CB), out · 0.7 pts
  • Kyler Murray (ARI QB), out, replaced by c.mccoy · 5.5 pts
  • J.J. Watt (ARI DE), out (IR) · 1.3 pts
  • DeAndre Hopkins (ARI WR), out · 1.2 pts
  • Justin Pugh (ARI G), out · 0.4 pts
  • Maxx Williams (ARI TE), out (IR) · 0.2 pts
  • Chase Edmonds (ARI RB), out (IR) · 0.1 pts
  • Aaron Brewer (ARI LS), out (IR) · 0.1 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

Cardinals 97% · Seahawks 3%

Final margin
Cardinals by 10
Luck in points
7.6 for the Seahawks
Luck-adjusted margin
Cardinals by 17.6
Replay with same day's form
Cardinals 64% · Seahawks 36% 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 11 2021 games · Cardinals · Seahawks

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