luckadjusted

Week 14 2021 · December 12, 2021

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

Raiders at Chiefs, Week 14 2021: who deserved to win?

The Chiefs beat the Raiders 48–9, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 10 of 10.

Before kickoff the Chiefs were 77% favorites. The biggest swing (Q1, 14:52 left): Return touchdown by the Chiefs, worth 28 points of win probability to the Chiefs.

Final

Las Vegas Raiders 9
Kansas City Chiefs 48

December 12, 2021 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −10

Luck index +4 Chiefs about even · −4 Raiders

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. Raiders win 0, Chiefs win 10.

  1. 1 LV 27 KC 30
  2. 2 LV 13 KC 20
  3. 3 LV 7 KC 16
  4. 4 LV 27 KC 38
  5. 5 LV 13 KC 27
  6. 6 LV 10 KC 27
  7. 7 LV 17 KC 37
  8. 8 LV 0 KC 23
  9. 9 LV 17 KC 44
  10. 10 LV 0 KC 33

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

Raiders win 4% of them, Chiefs 96%. The line is what actually happened: Chiefs by 39.

Show as a table
Final margin in the replaysShare of replays
Raiders by 17+0.1%
Raiders by 9–160.9%
Raiders by 1–83.2%
Level after regulation0.4%
Chiefs by 1–813.5%
Chiefs by 9–1619.2%
Chiefs by 17+62.8%

Where the luck was

Take the luck out

The final margin was Chiefs by 39. Remove the luck, one kind at a time, and it becomes Chiefs by 27.9.

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. Carlson, 26 yds made · 97% expected
  • H. Butker, 54 yds made · 60% expected
  • H. Butker, 37 yds made · 89% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

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 Raiders were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:52 The Raiders fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50Return touchdown by the ChiefsSpecial teams +28% KC LV: Punt
2 Q1 14:01 The Raiders converted 3rd & 53rd & 4th downs · 36% expected +2% LV LV: Punt
3 Q1 10:06 Offensive Holding on the Raiders (Bryan Edwards), 10 yardsJudgment calls · 1 flag in 886 snaps before, position avg 1 per 399 +3% KC KC: Touchdown
4 Q1 9:10 Defensive Holding on the Chiefs, 5 yards, wiping out the playJudgment calls +4% LV LV: Punt
5 Q1 6:48 The Raiders were stopped on 3rd & 33rd & 4th downs · 47% expected +3% KC LV: Punt
6 Q1 3:56 Defensive Offside on the Raiders (Yannick Ngakoue), 5 yardsPre-snap flags · 8 flags in 2140 snaps before, position avg 1 per 266 +2% KC KC: Touchdown
7 Q1 3:49 The Chiefs converted 3rd & 33rd & 4th downs · 57% expected +2% KC KC: Touchdown
8 Q2 15:00 The Chiefs converted 3rd & 83rd & 4th downs · 37% expected +3% KC KC: 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.

  • L'Jarius Sneed (KC CB), out · 0.7 pts
  • Mike Remmers (KC T), out (IR) · 0.6 pts
  • Darren Waller (LV TE), out · 0.3 pts
  • Denzel Perryman (LV LB), out · 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

Raiders 0% · Chiefs 100%

Final margin
Chiefs by 39
Luck in points
11.1 for the Chiefs
Luck-adjusted margin
Chiefs by 27.9
Replay with same day's form
Raiders 4% · Chiefs 96% 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 (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 14 2021 games · Raiders · Chiefs

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