luckadjusted

Week 1 2022 · September 11, 2022

Chiefs at Cardinals, Week 1 2022: who deserved to win?

The Chiefs beat the Cardinals 44–21, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 9 of 10. The Cardinals had the bounces: fumble bounces alone were worth 10 points of win probability to the Cardinals.

Before kickoff the Chiefs were 67% favorites. The biggest swing (Q1, 10:28 left): the Chiefs converted 3rd & 7, worth 8 points of win probability to the Chiefs.

Final

Kansas City Chiefs 44
Arizona Cardinals 21

September 11, 2022 · State Farm Stadium · Closing line: Chiefs −6

Luck index +7 Chiefs about even · −7 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. Chiefs win 9, Cardinals win 1.

  1. 1 KC 37 ARI 3
  2. 2 KC 47 ARI 20
  3. 3 KC 30 ARI 7
  4. 4 KC 44 ARI 24
  5. 5 KC 28 ARI 12
  6. 6 KC 36 ARI 23
  7. 7 KC 35 ARI 27
  8. 8 KC 16 ARI 10
  9. 9 KC 23 ARI 20
  10. 10 KC 10 ARI 17

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

Chiefs win 93% of them, Cardinals 7%, counting the 1% still level after regulation as half each. The line is what actually happened: Chiefs by 23.

Show as a table
Final margin in the replaysShare of replays
Chiefs by 17+58.9%
Chiefs by 9–1619.2%
Chiefs by 1–814.6%
Level after regulation0.7%
Cardinals by 1–84.7%
Cardinals by 9–161.6%
Cardinals by 17+0.4%

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 Chiefs: the final margin was Chiefs by 23, without the luck Chiefs by 18.4. 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, 54 yds made · 72% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Chiefs 3 for 25 yards, Cardinals 5 for 49 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 8:01 Illegal Block Above the Waist on the Chiefs (Deon Bush), 10 yards +3% ARI +1.0 pts
Q1 7:07 Roughing the Passer on the Cardinals (Zach Allen), 15 yards +4% KC +1.6 pts
Q1 4:25 Defensive Offside on the Cardinals, 5 yards · pre-snap +1% KC +0.4 pts
Q2 10:34 Unnecessary Roughness on the Cardinals, 15 yards +4% KC +1.8 pts
Q3 13:56 False Start on the Cardinals, 5 yards · pre-snap +1% KC +0.5 pts
Q3 10:07 Defensive Pass Interference on the Cardinals (Marco Wilson), 9 yards +1% KC +1.2 pts
Q3 5:14 Ineligible Downfield Pass on the Chiefs, 5 yards 0% ARI +1.1 pts
Q4 5:11 Offensive Holding on the Chiefs, 10 yards 0% ARI +0.9 pts

Chiefs penalties, every game · Cardinals penalties, every game · All teams, 2022

When it happened

Cardinals’ chance of winning

As low as 0% and as high as 57%. 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 Chiefs were.
#WhenWhat happenedWin probability forNext drive
1 Q1 10:28 The Chiefs converted 3rd & 73rd & 4th downs · 39% expected +8% KC KC: Touchdown
2 Q1 8:36 The Cardinals were stopped on 3rd & 13rd & 4th downs · 75% expected +7% KC ARI: Punt
3 Q1 0:45 The Cardinals fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +5% ARI ARI: Touchdown
4 Q2 10:34 Unnecessary Roughness on the Cardinals, 15 yardsJudgment calls +4% KC KC: Touchdown
5 Q2 7:37 The Chiefs converted 4th & 23rd & 4th downs · 57% expected +6% KC KC: Touchdown
6 Q2 2:00 The Cardinals fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +6% ARI ARI: Punt
7 Q2 1:05 The Chiefs fumbled and the Cardinals recoveredFumble bounces · loose balls are close to 50/50 +4% ARI KC: Field goal
8 Q2 0:40 The Cardinals were stopped on 4th & 23rd & 4th downs · 61% expected +5% KC ARI: End of half

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) · 1.1 pts
  • Antoine Wesley (ARI WR), out (IR) · 0.5 pts
  • Justin Pugh (ARI G), out · 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

Chiefs 100% · Cardinals 0%

Final margin
Chiefs by 23
Luck in points
4.6 for the Chiefs
Luck-adjusted margin
Chiefs by 18.4
Replay with same day's form
Chiefs 93% · Cardinals 7% 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 1 2022 games · Chiefs · Cardinals

More from Week 1 2022