luckadjusted
NFL Week 9 · 2026

Week 17 2023 · December 31, 2023

Chargers at Broncos, Week 17 2023: who deserved to win?

The Broncos beat the Chargers 16–9, and the replays lean their way: with the same day's form, they win 7 of 10.

Before kickoff the Broncos were 60% favorites.

Final

Los Angeles Chargers 9
Denver Broncos 16

December 31, 2023 · Empower Field at Mile High · Closing line: Broncos −3.5

Luck index +32 Broncos lucky · −32 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 3, Broncos win 7.

  1. 1 LAC 37 DEN 20
  2. 2 LAC 28 DEN 20
  3. 3 LAC 17 DEN 14
  4. 4 LAC 17 DEN 19
  5. 5 LAC 20 DEN 24
  6. 6 LAC 14 DEN 20
  7. 7 LAC 13 DEN 22
  8. 8 LAC 20 DEN 32
  9. 9 LAC 6 DEN 23
  10. 10 LAC 6 DEN 29

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 32% of them, Broncos 68%, counting the 4% still level after regulation as half each. The line is what actually happened: Broncos by 7.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+3.8%
Chargers by 9–168.0%
Chargers by 1–816.3%
Level after regulation4.2%
Broncos by 1–825.9%
Broncos by 9–1621.9%
Broncos by 17+20.0%

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 +8.5 points to the Broncos: the final margin was Broncos by 7, without the luck Chargers by 1.5. 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.

  • W. Lutz, 32 yds made · 94% expected
  • C. Dicker, 36 yds made · 93% expected
  • W. Lutz, 43 yds made · 83% expected
  • W. Lutz, 48 yds missed · 72% expected
  • C. Dicker, 50 yds made · 72% expected
  • W. Lutz, 20 yds made · 98% expected
  • C. Dicker, 50 yds blocked · 73% expected
  • C. Dicker, 52 yds made · 70% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Chargers 3 for 48 yards, Broncos 7 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 half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued

WhenFlagWin probability for
Q1 3:58 Delay of Game on the Broncos, 5 yards · pre-snap +2% LAC +0.4 pts
Q2 14:31 Offensive Holding on the Broncos, 10 yards, wiping out the play +6% LAC +1.9 pts
Q2 5:18 Offensive Holding on the Chargers, 10 yards +3% DEN +1.3 pts
Q2 1:01 Offensive Holding on the Chargers, 10 yards +3% DEN +1.3 pts
Q3 10:12 Neutral Zone Infraction on the Broncos, 5 yards · pre-snap +2% LAC +0.8 pts
Q4 12:52 Defensive Pass Interference on the Chargers (Alohi Gilman), 28 yards +6% DEN +4.0 pts
Q4 12:45 False Start on the Broncos, 5 yards · pre-snap +1% LAC +0.8 pts
Q4 12:45 False Start on the Broncos, 5 yards · pre-snap +1% LAC +0.9 pts
Q4 3:58 Offensive Holding on the Broncos, 10 yards +1% LAC +0.9 pts
Q4 2:00 Defensive Pass Interference on the Broncos, 9 yards +1% LAC +0.9 pts

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

When it happened

Broncos’ 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 Broncos were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 0:24 The Broncos got away with an interception-worthy throwInterceptions · defenses catch 50% of interception-worthy throws +5% DEN DEN: Punt
2 Q2 14:31 Offensive Holding on the Broncos, 10 yards, wiping out the playJudgment calls +5% LAC LAC: Field goal
3 Q2 9:51 The Chargers were stopped on 3rd & 83rd & 4th downs · 31% expected +4% DEN LAC: Field goal
4 Q2 6:52 The Broncos converted 3rd & 83rd & 4th downs · 30% expected +7% DEN DEN: Touchdown
5 Q2 0:04 W. Lutz missed a 48-yard field goalKicks · 72% expected for him, 27 of 40 from 45+ before +5% LAC DEN: Punt
6 Q3 13:42 The Broncos converted 3rd & 103rd & 4th downs · 26% expected +5% DEN DEN: Punt
7 Q4 15:00 The Chargers fumbled and the Broncos recoveredFumble bounces · loose balls are close to 50/50 +5% DEN LAC: Missed field goal
8 Q4 12:52 Defensive Pass Interference on the Chargers (Alohi Gilman), 28 yardsJudgment calls · 4 flags in 2523 snaps before, position avg 1 per 462 +6% DEN DEN: Field goal

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.

  • Courtland Sutton (DEN WR), out · 0.8 pts
  • Baron Browning (DEN LB), out · 0.2 pts
  • Justin Herbert (LAC QB), out (IR), replaced by e.stick · 6.3 pts
  • Keenan Allen (LAC WR), out · 1.1 pts
  • Joey Bosa (LAC DE), out (IR) · 0.7 pts
  • Josh Palmer (LAC WR), out · 0.6 pts
  • Zion Johnson (LAC G), out · 0.5 pts
  • Kenneth Murray (LAC LB), out · 0.4 pts
  • Deane Leonard (LAC CB), out · 0.4 pts
  • Will Clapp (LAC C), out (IR) · 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

Chargers 24% · Broncos 76%

Final margin
Broncos by 7
Luck in points
8.5 for the Broncos
Luck-adjusted margin
Chargers by 1.5
Replay with same day's form
Chargers 32% · Broncos 68% unchanged: why
How much of each is luck?

0% treats it as skill, 100% as pure luck. The tick is our fit.

What counts

None by default: our tests measured no carryover after a lucky break. Slide it up to count a break for more than its own swing. 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 17 2023 games · Chargers · Broncos

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