luckadjusted

Week 12 2021 · November 28, 2021

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

Chargers at Broncos, Week 12 2021: who deserved to win?

The Broncos beat the Chargers 28–13, but the Chargers played well enough to win it: they take 6 of 10 replays with the same day's form. Luck ran their way: judgment calls alone were worth 8 points of win probability to the Broncos.

Before kickoff the Chargers were 57% favorites. The biggest swing (Q3, 1:29 left): the Chargers converted 4th & 4, worth 11 points of win probability to the Chargers.

Final

Los Angeles Chargers 13
Denver Broncos 28

November 28, 2021 · Empower Field at Mile High · Closing line: Chargers −2.5

Luck index +61 Broncos very lucky · −61 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 6, Broncos win 4.

  1. 1 LAC 30 DEN 7
  2. 2 LAC 26 DEN 10
  3. 3 LAC 20 DEN 10
  4. 4 LAC 31 DEN 24
  5. 5 LAC 22 DEN 17
  6. 6 LAC 15 DEN 13
  7. 7 LAC 26 DEN 28
  8. 8 LAC 23 DEN 28
  9. 9 LAC 13 DEN 23
  10. 10 LAC 7 DEN 23

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

Chargers win 61% of them, Broncos 39%, counting the 4% still level after regulation as half each. The line is what actually happened: Broncos by 15.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+12.3%
Chargers by 9–1616.8%
Chargers by 1–830.5%
Level after regulation3.5%
Broncos by 1–820.3%
Broncos by 9–1611.8%
Broncos by 17+4.8%

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 +11.5 points to the Broncos: the final margin was Broncos by 15, without the luck Broncos by 3.5. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Chargers 9 for 75 yards, Broncos 5 for 35 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 11:15 Offensive Holding on the Broncos, 10 yards +6% LAC +1.5 pts
Q1 7:46 Defensive Holding on the Chargers, 5 yards +3% DEN +0.9 pts
Q2 12:09 Offensive Pass Interference on the Chargers (Mike Williams), 10 yards, wiping out the play +7% DEN +4.1 pts
Q2 8:20 Offensive Holding on the Chargers, 10 yards +1% DEN +1.3 pts
Q2 2:00 Defensive Pass Interference on the Chargers, 15 yards +2% DEN +1.4 pts
Q2 2:00 False Start on the Broncos, 5 yards · pre-snap +2% LAC +0.3 pts
Q3 15:00 Offensive Holding on the Chargers (Donald Parham), 10 yards +2% DEN +0.9 pts
Q3 13:45 Defensive Holding on the Broncos (Dre'Mont Jones), 5 yards +3% LAC +0.8 pts
Q3 12:01 Offensive Holding on the Chargers, 10 yards +1% DEN +1.0 pts
Q3 11:05 False Start on the Chargers, 5 yards · pre-snap +3% DEN +1.2 pts
Q3 7:18 Offensive Holding on the Broncos, 10 yards +3% LAC +1.1 pts
Q3 4:39 Defensive Holding on the Broncos (Ronald Darby), 5 yards, wiping out the play +4% LAC +2.0 pts
Q4 15:00 Ineligible Downfield Pass on the Chargers, 5 yards, wiping out the play +6% DEN +1.6 pts
Q4 10:52 Roughing the Passer on the Chargers (Jerry Tillery), 5 yards +1% DEN +0.6 pts

Chargers penalties, every game · Broncos penalties, every game · All teams, 2021

When it happened

Broncos’ chance of winning

As low as 49% 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 Broncos were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:29 The Broncos converted 3rd & 83rd & 4th downs · 31% expected +7% DEN DEN: Punt
2 Q1 1:31 The Broncos converted 3rd & 33rd & 4th downs · 51% expectedThe Broncos fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +8% DEN DEN: Touchdown
3 Q2 12:09 Offensive Pass Interference on the Chargers (Mike Williams), 10 yards, wiping out the playJudgment calls · 4 flags in 2173 snaps before, position avg 1 per 399 +7% DEN DEN: Punt
4 Q3 8:41 The Chargers were stopped on 3rd & 63rd & 4th downs · 37% expected +9% DEN LAC: Missed field goal
5 Q3 7:58 D. Hopkins missed 52-yard field goalKicks · 71% expected for him, 18 of 25 from 45+ before +6% DEN LAC: Turnover
6 Q3 1:29 The Chargers converted 4th & 43rd & 4th downs · 45% expected +11% LAC LAC: Turnover
7 Q4 15:00 Ineligible Downfield Pass on the Chargers, 5 yards, wiping out the playJudgment calls +6% DEN DEN: Touchdown
8 Q4 14:37 The Chargers were stopped on 3rd & 143rd & 4th downs · 23% expected +8% DEN LAC: Opp 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.

  • Garett Bolles (DEN T), out (IR) · 1.0 pts
  • Bobby Massie (DEN T), out · 0.8 pts
  • Kareem Jackson (DEN SS), out · 0.5 pts
  • Graham Glasgow (DEN G), out (IR) · 0.4 pts
  • Bryce Callahan (DEN CB), out (IR) · 0.4 pts
  • Shelby Harris (DEN DE), out · 0.3 pts
  • Matt Feiler (LAC G), out · 0.3 pts
  • Linval Joseph (LAC NT), out (IR) · 0.3 pts
  • Oday Aboushi (LAC G), 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

Chargers 38% · Broncos 62%

Final margin
Broncos by 15
Luck in points
11.5 for the Broncos
Luck-adjusted margin
Broncos by 3.5
Replay with same day's form
Chargers 61% · Broncos 39% 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 12 2021 games · Chargers · Broncos

More from Week 12 2021