luckadjusted

Week 2 2022 · September 15, 2022

Chargers at Chiefs, Week 2 2022: who deserved to win?

The Chiefs beat the Chargers 27–24, but the Chargers played well enough to win it: they take 7 of 10 replays with the same day's form. Luck ran their way: judgment calls alone were worth 2.1 points to the Chiefs.

The Chiefs won on an off day: their offense played far below its usual level. In a fresh game against the Chargers they would win 66% of the time; with this day’s form, 33%. The numbers

Before kickoff the Chiefs were 62% favorites. The biggest swing (Q4, 10:43 left): Return touchdown by the Chiefs, worth 56 points of win probability to the Chiefs.

Final

Los Angeles Chargers 24
Kansas City Chiefs 27

September 15, 2022 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −4

Luck index +67 Chiefs very lucky · −67 Chargers

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. Chargers win 7, Chiefs win 3.

  1. 1 LAC 38 KC 10
  2. 2 LAC 41 KC 21
  3. 3 LAC 37 KC 21
  4. 4 LAC 31 KC 20
  5. 5 LAC 17 KC 10
  6. 6 LAC 31 KC 27
  7. 7 LAC 31 KC 29
  8. 8 LAC 13 KC 16
  9. 9 LAC 20 KC 28
  10. 10 LAC 20 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.

The Chiefs won on an off day

Their offense played far below its usual level. In a fresh game against the Chargers they would win 66% of the time; with this day’s form, 33%.

33 points apart for the Chiefs: the gap is how differently this game went from what the two teams usually are.

UnitThis gameUsual levelBetter or worse than usual
Chargers offenseEPA per play gained +0.11 +0.17 worse by 0.05
Chargers defenseEPA per play allowed +0.11 +0.12 better by 0.01
Chiefs offenseEPA per play gained +0.11 +0.22 worse by 0.11
Chiefs defenseEPA per play allowed +0.11 +0.12 better by 0.01

EPA (expected points added) per play on competitive snaps, turnovers left out because they are valued as luck. Usual level: the team’s earlier games this season plus half of last season, pulled toward the league average. One team’s defense and the other team’s offense are the same snaps, so one game can’t fully say whose day it was; it shows how far this one was from both teams’ norms.

How 4,000 replays ended

Chargers win 67% of them, Chiefs 33%, counting the 3% still level after regulation as half each. The line is what actually happened: Chiefs by 3.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+23.0%
Chargers by 9–1620.6%
Chargers by 1–822.6%
Level after regulation2.9%
Chiefs by 1–816.7%
Chiefs by 9–169.0%
Chiefs by 17+5.3%

Where the luck was

Take the luck out

The final margin was Chiefs by 3. Remove the luck, one kind at a time, and it becomes Chiefs by 3.9.

Each row takes one kind of luck out of the margin. Color shows which team it helped. Luck shares are the fitted ones (how much of each component is luck).

The kicks

How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.

  • D. Hopkins, 31 yds made · 95% expected
  • M. Ammendola, 19 yds made · 98% expected
  • M. Ammendola, 31 yds made · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Chiefs’ chance of winning

As low as 19% 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 Chiefs were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:03 The Chargers converted 3rd & 23rd & 4th downs · 61% expected +8% LAC LAC: Field goal
2 Q2 13:38 Illegal Contact on the Chargers, 5 yards, wiping out the playJudgment calls +14% KC KC: Touchdown
3 Q3 7:28 The Chiefs converted 3rd & 103rd & 4th downs · 32% expected +16% KC KC: Touchdown
4 Q3 4:47 The Chargers were stopped on 3rd & 103rd & 4th downs · 28% expected +7% KC LAC: Punt
5 Q3 3:16 The Chiefs converted 3rd & 103rd & 4th downs · 32% expected +9% KC KC: Field goal
6 Q3 0:34 The Chiefs got away with an interception-worthy throwInterceptions · 49% expected to stay out of the defense's hands +9% KC KC: Field goal
7 Q4 15:00 M. Ammendola made 19-yard field goalKicks · 98% expected for him +10% LAC KC: Opp touchdown
8 Q4 10:43 The Chargers threw an interception-worthy pass, and it was pickedInterceptions · 48% expected to stay out of the defense's handsReturn touchdown by the ChiefsSpecial teams +56% KC LAC: 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.

  • Harrison Butker (KC K), out · 0.5 pts
  • Lucas Niang (KC T), out (IR) · 0.2 pts
  • Keenan Allen (LAC WR), out · 1.0 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

Chargers 29% · Chiefs 71%

Final margin
Chiefs by 3
Luck in points
0.9 for the Chargers
Luck-adjusted margin
Chiefs by 3.9
Replay with same day's form
Chargers 67% · Chiefs 33% 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 2 2022 games · Chargers · Chiefs

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