luckadjusted
NFL Week 9 · 2026

Week 1 2023 · September 10, 2023

Dolphins at Chargers, Week 1 2023: who deserved to win?

The Dolphins beat the Chargers 36–34, but the replays call it close to a coin flip: with the way both teams played, the Dolphins win 4 of 10. Luck ran their way: 3rd & 4th downs alone were worth 10 points of win probability to the Dolphins.

Before kickoff the Chargers were 59% favorites. The biggest swing (Q4, 3:47 left): the Dolphins converted 3rd & 10, worth 15 points of win probability to the Dolphins.

Final

Miami Dolphins 36
Los Angeles Chargers 34

September 10, 2023 · SoFi Stadium · Closing line: Chargers −3

Luck index +56 Dolphins lucky · −56 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. Dolphins win 4, Chargers win 6.

  1. 1 MIA 44 LAC 23
  2. 2 MIA 26 LAC 13
  3. 3 MIA 37 LAC 30
  4. 4 MIA 38 LAC 35
  5. 5 MIA 20 LAC 22
  6. 6 MIA 14 LAC 19
  7. 7 MIA 27 LAC 36
  8. 8 MIA 21 LAC 34
  9. 9 MIA 13 LAC 30
  10. 10 MIA 3 LAC 28

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

Dolphins win 44% of them, Chargers 56%, counting the 4% still level after regulation as half each. The line is what actually happened: Dolphins by 2.

Show as a table
Final margin in the replaysShare of replays
Dolphins by 17+8.8%
Dolphins by 9–1612.7%
Dolphins by 1–819.4%
Level after regulation3.5%
Chargers by 1–824.9%
Chargers by 9–1616.4%
Chargers by 17+14.2%

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 +0.5 points to the Chargers: the final margin was Dolphins by 2, without the luck Dolphins by 2.5. 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.

  • J. Sanders, 23 yds made · 98% expected
  • C. Dicker, 50 yds made · 73% expected
  • J. Sanders, 41 yds made · 88% expected
  • J. Sanders, 45 yds made · 81% expected
  • C. Dicker, 25 yds made · 98% expected
  • Extra point missed · 96% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Dolphins 6 for 38 yards, Chargers 6 for 70 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 15:00 Defensive Offside on the Chargers (Joey Bosa), 5 yards · pre-snap 0% MIA +0.4 pts
Q1 2:31 Offensive Holding on the Dolphins, 10 yards +3% LAC +0.9 pts
Q1 2:10 Face Mask on the Chargers (Joey Bosa), 14 yards +4% MIA +0.9 pts
Q2 15:00 False Start on the Chargers, 5 yards · pre-snap +4% MIA +0.9 pts
Q2 4:21 False Start on the Dolphins, 5 yards · pre-snap +4% LAC +0.7 pts
Q2 0:02 Defensive Pass Interference on the Chargers, 30 yards +13% MIA +2.0 pts
Q3 10:04 Defensive Pass Interference on the Dolphins (Xavien Howard), 13 yards +4% LAC +1.2 pts
Q3 9:24 Defensive Pass Interference on the Dolphins (Xavien Howard), 5 yards +4% LAC +1.1 pts
Q3 9:20 Defensive Too Many Men on Field on the Dolphins, 0 yards · pre-snap 0% LAC 0.0 pts
Q4 7:23 Illegal Shift on the Chargers, 5 yards · pre-snap +2% MIA +0.6 pts
Q4 5:15 Illegal Contact on the Dolphins (Xavien Howard), 5 yards +1% LAC +0.2 pts
Q4 1:38 Intentional Grounding on the Chargers (Justin Herbert), 11 yards +6% MIA +1.0 pts

Dolphins 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 84%. 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 Dolphins were.
#WhenWhat happenedWin probability forNext drive
1 Q1 12:11 The Dolphins fumbled and the Chargers recoveredFumble bounces · loose balls are close to 50/50 +11% LAC MIA: Touchdown
2 Q2 3:09 The Dolphins converted 4th & 73rd & 4th downs · 36% expected +10% MIA MIA: Touchdown
3 Q2 0:02 Defensive Pass Interference on the Chargers, 30 yardsJudgment calls +13% MIA MIA: Field goal
4 Q4 13:04 The Dolphins converted 3rd & 153rd & 4th downs · 22% expected +10% MIA MIA: Field goal
5 Q4 3:47 The Dolphins converted 3rd & 103rd & 4th downs · 29% expected +15% MIA MIA: Touchdown
6 Q4 1:48 The Dolphins converted 3rd & 43rd & 4th downs · 40% expected +12% MIA MIA: Touchdown
7 Q4 1:45 The Dolphins missed an extra pointKicks · extra points are made about 94% of the time +9% LAC MIA: End of game
8 Q4 1:01 The Chargers were stopped on 4th & 123rd & 4th downs · 28% expected +14% MIA –

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.

  • Terron Armstead (MIA T), out · 1.0 pts
  • Robert Jones (MIA G), out (IR) · 0.3 pts
  • Keion Crossen (MIA CB), 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

Dolphins 59% · Chargers 41%

Final margin
Dolphins by 2
Luck in points
0.5 for the Chargers
Luck-adjusted margin
Dolphins by 2.5
Replay with same day's form
Dolphins 44% · Chargers 56% 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 1 2023 games · Dolphins · Chargers

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