luckadjusted
NFL Week 9 · 2026

Week 16 2021 · December 25, 2021

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

Colts at Cardinals, Week 16 2021: who deserved to win?

The Colts beat the Cardinals 22–16, but the replays call it close to a coin flip: with the way both teams played, the Colts win 6 of 10. Luck ran their way: kicks alone were worth 30 points of win probability to the Colts.

Before kickoff the Cardinals were 59% favorites. The game turned on a luck play (Q4, 11:12 left): M. Prater missed a 41-yard field goal, worth 20 points of win probability to the Colts.

Final

Indianapolis Colts 22
Arizona Cardinals 16

December 25, 2021 · State Farm Stadium · Closing line: Cardinals −3

Luck index +40 Colts lucky · −40 Cardinals

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. Colts win 6, Cardinals win 4.

  1. 1 IND 35 ARI 12
  2. 2 IND 22 ARI 7
  3. 3 IND 23 ARI 12
  4. 4 IND 38 ARI 30
  5. 5 IND 23 ARI 17
  6. 6 IND 9 ARI 6
  7. 7 IND 20 ARI 21
  8. 8 IND 17 ARI 22
  9. 9 IND 17 ARI 26
  10. 10 IND 13 ARI 32

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

Colts win 60% of them, Cardinals 40%, counting the 3% still level after regulation as half each. The line is what actually happened: Colts by 6.

Show as a table
Final margin in the replaysShare of replays
Colts by 17+13.5%
Colts by 9–1616.4%
Colts by 1–828.4%
Level after regulation3.2%
Cardinals by 1–819.4%
Cardinals by 9–1611.8%
Cardinals by 17+7.3%

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 +5.7 points to the Colts: the final margin was Colts by 6, without the luck Colts by 0.3. 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.

  • M. Prater, 51 yds missed · 71% expected
  • M. Badgley, 53 yds missed · 61% expected
  • M. Badgley, 41 yds made · 87% expected
  • M. Badgley, 37 yds made · 91% expected
  • M. Prater, 41 yds missed · 88% expected
  • M. Prater, 28 yds made · 96% expected
  • Extra point missed · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Colts 5 for 40 yards, Cardinals 11 for 85 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 13:13 False Start on the Cardinals, 5 yards · pre-snap +3% IND +0.7 pts
Q1 1:09 Defensive Offside on the Cardinals (Corey Peters), 5 yards · pre-snap +2% IND +0.7 pts
Q1 0:46 Neutral Zone Infraction on the Cardinals (Leki Fotu), 5 yards · pre-snap +1% IND +0.4 pts
Q2 10:37 False Start on the Cardinals, 4 yards · pre-snap +3% IND +1.0 pts
Q2 8:14 Illegal Contact on the Cardinals (Byron Murphy), 5 yards, wiping out the play +7% IND +2.2 pts
Q2 7:28 False Start on the Colts, 5 yards · pre-snap +1% ARI +0.3 pts
Q2 6:33 False Start on the Colts, 5 yards · pre-snap +1% ARI +0.8 pts
Q2 4:25 Intentional Grounding on the Cardinals (Kyler Murray), 11 yards +4% IND +0.9 pts
Q2 0:52 Defensive Pass Interference on the Cardinals (Marco Wilson), 12 yards +2% IND +0.7 pts
Q2 0:47 Offensive Holding on the Colts, 10 yards, wiping out the play +4% ARI +2.3 pts
Q2 0:21 Offensive Pass Interference on the Colts (Michael Pittman Jr.), 10 yards, wiping out the play +4% ARI +1.0 pts
Q3 14:57 Roughing the Passer on the Cardinals (Chandler Jones), 15 yards +5% IND +1.2 pts
Q4 10:23 Offensive Holding on the Colts, 10 yards +4% ARI +1.0 pts
Q4 6:45 Roughing the Passer on the Cardinals (Zach Allen), 8 yards +2% IND +0.7 pts
Q4 2:22 Offensive Holding on the Cardinals, 10 yards, wiping out the play +8% IND +2.1 pts
Q4 2:00 False Start on the Cardinals, 5 yards · pre-snap 0% IND +0.6 pts

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

When it happened

Cardinals’ chance of winning

As low as 0% and as high as 66%. 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 Cardinals were ahead in it, below while the Colts were.
#WhenWhat happenedWin probability forNext drive
1 Q2 14:14 M. Badgley missed a 53-yard field goalKicks · 61% expected for him, 7 of 19 from 45+ before +11% ARI IND: Punt
2 Q2 10:14 The Cardinals were stopped on 4th & 53rd & 4th downs · 46% expected +10% IND ARI: Safety
3 Q2 8:58 The Colts converted 3rd & 43rd & 4th downs · 47% expected +8% IND IND: Punt
4 Q3 5:45 The Colts were stopped on 4th & 43rd & 4th downs · 47% expected +10% ARI IND: Field goal
5 Q4 13:10 The Cardinals converted 3rd & 103rd & 4th downs · 31% expected +12% ARI ARI: Missed field goal
6 Q4 11:12 The game turned hereM. Prater missed a 41-yard field goalKicks · 88% expected for him +20% IND ARI: Turnover on downs
7 Q4 6:45 The Colts converted 3rd & 93rd & 4th downs · 30% expectedRoughing the Passer on the Cardinals (Zach Allen), 8 yardsJudgment calls · 4 flags in 1315 snaps before, position avg 1 per 266 +11% IND IND: Touchdown
8 Q4 2:22 Offensive Holding on the Cardinals, 10 yards, wiping out the playJudgment calls +8% IND IND: End of game

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.

  • DeAndre Hopkins (ARI WR), out (IR) · 1.0 pts
  • Rodney Hudson (ARI C), out (IR) · 0.6 pts
  • James Conner (ARI RB), out · 0.4 pts
  • Robert Alford (ARI CB), out (IR) · 0.4 pts
  • Jordan Phillips (ARI DE), out · 0.3 pts
  • Andy Lee (ARI P), out (IR) · 0.2 pts
  • Quenton Nelson (IND G), out (IR) · 0.8 pts
  • Ryan Kelly (IND C), out · 0.6 pts
  • Zach Pascal (IND WR), out · 0.6 pts
  • Khari Willis (IND SS), out · 0.5 pts
  • Andrew Sendejo (IND FS), out · 0.4 pts
  • Rock Ya-Sin (IND CB), out (IR) · 0.4 pts
  • Mark Glowinski (IND G), out (IR) · 0.3 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

Colts 48% · Cardinals 52%

Final margin
Colts by 6
Luck in points
5.7 for the Colts
Luck-adjusted margin
Colts by 0.3
Replay with same day's form
Colts 60% · Cardinals 40% 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 16 2021 games · Colts · Cardinals

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