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).

Cowboys at Chiefs, Week 11 2021: who deserved to win?

The Chiefs beat the Cowboys 19–9, and the replays back it up: with the way both teams actually played, the Chiefs win 8 of 10. The Cowboys had the bounces: kicks alone were worth 13 points of win probability to the Cowboys.

Before kickoff the Chiefs were 57% favorites.

Final

Dallas Cowboys 9
Kansas City Chiefs 19

November 21, 2021 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −2.5

Luck index +16 Chiefs about even · −16 Cowboys

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. Cowboys win 2, Chiefs win 8.

  1. 1 DAL 29 KC 17
  2. 2 DAL 23 KC 20
  3. 3 DAL 37 KC 39
  4. 4 DAL 29 KC 34
  5. 5 DAL 23 KC 31
  6. 6 DAL 20 KC 31
  7. 7 DAL 21 KC 37
  8. 8 DAL 21 KC 40
  9. 9 DAL 7 KC 33
  10. 10 DAL 6 KC 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

Cowboys win 16% of them, Chiefs 84%, counting the 2% still level after regulation as half each. The line is what actually happened: Chiefs by 10.

Show as a table
Final margin in the replaysShare of replays
Cowboys by 17+2.0%
Cowboys by 9–164.4%
Cowboys by 1–89.7%
Level after regulation1.6%
Chiefs by 1–818.5%
Chiefs by 9–1622.1%
Chiefs by 17+41.7%

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 +4.0 points to the Cowboys: the final margin was Chiefs by 10, without the luck Chiefs by 14. 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.

  • H. Butker, 37 yds made · 90% expected
  • G. Zuerlein, 33 yds made · 92% expected
  • G. Zuerlein, 30 yds made · 94% expected
  • H. Butker, 53 yds made · 63% expected
  • G. Zuerlein, 48 yds made · 67% expected
  • H. Butker, 51 yds missed · 66% expected
  • Extra point missed · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Cowboys 6 for 45 yards, Chiefs 5 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 half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued

WhenFlagWin probability for
Q1 10:43 Encroachment on the Cowboys, 5 yards · pre-snap +1% KC +0.9 pts
Q1 3:22 False Start on the Cowboys, 5 yards · pre-snap +3% KC +0.5 pts
Q1 2:43 Offensive Holding on the Chiefs, 10 yards +1% DAL +0.9 pts
Q2 14:13 Taunting on the Chiefs (Clyde Edwards-Helaire), 15 yards +3% DAL +1.1 pts
Q2 12:22 Offensive Too Many Men on Field on the Cowboys, 5 yards · pre-snap +1% KC +0.5 pts
Q2 10:10 Offensive Holding on the Cowboys, 10 yards, wiping out the play +6% KC +2.5 pts
Q2 9:43 Illegal Use of Hands on the Chiefs (L'Jarius Sneed), 5 yards +2% DAL +1.6 pts
Q2 3:48 Offensive Holding on the Chiefs, 14 yards +2% DAL +1.9 pts
Q3 12:41 Offensive Holding on the Chiefs, 10 yards, wiping out the play +1% DAL +1.5 pts
Q4 15:00 False Start on the Cowboys, 5 yards · pre-snap +2% KC +0.7 pts
Q4 12:52 Unnecessary Roughness on the Cowboys (Chauncey Golston), 15 yards +3% KC +1.8 pts

Cowboys penalties, every game · Chiefs penalties, every game · All teams, 2021

When it happened

Chiefs’ chance of winning

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 Chiefs were ahead in it, below while the Cowboys were.
#WhenWhat happenedWin probability forNext drive
1 Q1 3:22 False Start on the Cowboys, 5 yardsPre-snap flags +3% KC KC: Touchdown
2 Q1 2:54 G. Zuerlein made a 33-yard field goalKicks · 92% expected for him +6% DAL DAL: Punt
3 Q2 10:10 Offensive Holding on the Cowboys, 10 yards, wiping out the playJudgment calls +6% KC KC: Punt
4 Q2 1:39 The Chiefs fumbled and the Cowboys recoveredFumble bounces · loose balls are close to 50/50 +3% DAL KC: End of half
5 Q3 10:43 The Cowboys converted 3rd & 73rd & 4th downs · 34% expected +4% DAL DAL: Field goal
6 Q3 2:42 H. Butker made a 53-yard field goalKicks · 63% expected for him, 19 of 25 from 45+ before +7% KC KC: Missed field goal
7 Q4 12:57 G. Zuerlein made a 48-yard field goalKicks · 67% expected for him, 24 of 36 from 45+ before +5% DAL DAL: Punt
8 Q4 9:49 H. Butker missed a 51-yard field goalKicks · 66% expected for him, 20 of 26 from 45+ before +6% DAL KC: Punt

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.

  • Mike Remmers (KC T), out (IR) · 0.6 pts
  • Lucas Niang (KC T), out · 0.4 pts
  • Tyron Smith (DAL T), out · 1.2 pts
  • Amari Cooper (DAL WR), out (IR) · 1.1 pts
  • Randy Gregory (DAL DE), out (IR) · 0.3 pts
  • Blake Jarwin (DAL TE), out (IR) · 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

Cowboys 1% · Chiefs 99%

Final margin
Chiefs by 10
Luck in points
4.0 for the Cowboys
Luck-adjusted margin
Chiefs by 14.0
Replay with same day's form
Cowboys 16% · Chiefs 84% 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 · Cowboys · Chiefs

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