luckadjusted

Week 16 2023 · December 23, 2023

Bills at Chargers, Week 16 2023: who deserved to win?

The Bills beat the Chargers 24–22, and it was no fluke: replayed with the way both teams actually played, the Bills win 8 of 10. The Chargers had the bounces: judgment calls alone were worth 42 points of win probability to the Chargers.

Before kickoff the Bills were 83% favorites. The biggest swing (Q4, 6:13 left): the Chargers were stopped on 3rd & 5, worth 20 points of win probability to the Bills.

Final

Buffalo Bills 24
Los Angeles Chargers 22

December 23, 2023 · SoFi Stadium · Closing line: Bills −13

Luck index +16 Bills about even · −16 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. Bills win 8, Chargers win 2.

  1. 1 BUF 30 LAC 0
  2. 2 BUF 26 LAC 3
  3. 3 BUF 34 LAC 16
  4. 4 BUF 17 LAC 3
  5. 5 BUF 24 LAC 12
  6. 6 BUF 20 LAC 12
  7. 7 BUF 23 LAC 17
  8. 8 BUF 22 LAC 20
  9. 9 BUF 21 LAC 24
  10. 10 BUF 13 LAC 25

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

Bills win 84% of them, Chargers 16%, counting the 1% still level after regulation as half each. The line is what actually happened: Bills by 2.

Show as a table
Final margin in the replaysShare of replays
Bills by 17+38.2%
Bills by 9–1622.2%
Bills by 1–823.1%
Level after regulation0.8%
Chargers by 1–810.1%
Chargers by 9–164.3%
Chargers by 17+1.3%

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 +6.4 points to the Chargers: the final margin was Bills by 2, without the luck Bills by 8.4. 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.

  • C. Dicker, 20 yds made · 100% expected
  • C. Dicker, 40 yds made · 90% expected
  • C. Dicker, 47 yds made · 81% expected
  • C. Dicker, 45 yds made · 85% expected
  • C. Dicker, 53 yds made · 72% expected
  • T. Bass, 29 yds made · 97% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Bills 7 for 64 yards, Chargers 6 for 29 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 6:32 Offensive Holding on the Bills (Baylon Spector), 10 yards +3% LAC +0.8 pts
Q1 2:52 Illegal Shift on the Chargers, 5 yards · pre-snap +2% BUF +1.3 pts
Q1 2:31 Defensive Holding on the Bills (Christian Benford), 5 yards, wiping out the play +11% LAC +4.9 pts
Q2 11:58 Offensive Holding on the Bills, 10 yards +4% LAC +1.5 pts
Q2 5:51 Offensive Holding on the Chargers, 10 yards, wiping out the play +4% BUF +1.9 pts
Q3 14:58 Unnecessary Roughness on the Bills (Taron Johnson), 15 yards +5% LAC +2.1 pts
Q3 9:49 Illegal Formation on the Chargers, 5 yards, wiping out the play · pre-snap +7% BUF +1.9 pts
Q4 12:01 Tripping on the Bills, 15 yards, wiping out the play +7% LAC +2.3 pts
Q4 11:35 Offensive Holding on the Bills, 7 yards, wiping out the play +15% LAC +3.4 pts
Q4 9:28 False Start on the Bills (Siran Neal), 2 yards · pre-snap 0% LAC 0.0 pts
Q4 8:49 Illegal Shift on the Chargers, 5 yards · pre-snap +9% BUF +0.7 pts
Q4 6:13 False Start on the Chargers, 4 yards · pre-snap +6% BUF +0.8 pts
Q4 0:01 Illegal Forward Pass on the Chargers (Alex Erickson), 0 yards 0% BUF 0.0 pts

Bills penalties, every game · Chargers penalties, every game · All teams, 2023

When it happened

Chargers’ chance of winning

As low as 0% and as high as 85%. 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 Chargers were ahead in it, below while the Bills were.
#WhenWhat happenedWin probability forNext drive
1 Q4 11:35 Offensive Holding on the Bills, 7 yards, wiping out the playJudgment calls +15% LAC LAC: Field goal
2 Q4 10:20 The Bills were stopped on 3rd & 233rd & 4th downs · 18% expected +13% LAC BUF: Punt
3 Q4 7:19 The Bills fumbled and the Chargers recoveredFumble bounces · loose balls are close to 50/50 +14% LAC BUF: Field goal
4 Q4 6:13 The Chargers were stopped on 3rd & 53rd & 4th downs · 40% expectedFalse Start on the Chargers, 4 yardsPre-snap flags +20% BUF LAC: Field goal
5 Q4 2:56 The Bills converted 3rd & 83rd & 4th downs · 34% expected +13% BUF BUF: Field goal
6 Q4 0:31 T. Bass made 29-yard field goalKicks · 97% expected for him +17% BUF –
7 Q4 0:07 The Chargers got away with an interception-worthy throwInterceptions · 47% expected to stay out of the defense's hands +15% LAC LAC: End of game
8 Q4 0:01 The Chargers were stopped on 3rd & 193rd & 4th downs · 17% expectedIllegal Forward Pass on the Chargers (Alex Erickson), 0 yardsJudgment calls · 0 flags in 1354 snaps before, position avg 1 per 420 +15% BUF –

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.

  • Justin Herbert (LAC QB), out (IR), replaced by e.stick · 6.3 pts
  • Keenan Allen (LAC WR), out · 1.0 pts
  • Joey Bosa (LAC DE), out (IR) · 0.7 pts
  • Donald Parham (LAC TE), out · 0.3 pts
  • Will Clapp (LAC C), out (IR) · 0.3 pts
  • Deane Leonard (LAC CB), out · 0.2 pts
  • Micah Hyde (BUF FS), out · 0.6 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

Bills 96% · Chargers 4%

Final margin
Bills by 2
Luck in points
6.4 for the Chargers
Luck-adjusted margin
Bills by 8.4
Replay with same day's form
Bills 84% · Chargers 16% 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 16 2023 games · Bills · Chargers

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