luckadjusted
NFL Week 9 · 2026

Week 4 2019 · September 29, 2019

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

Chargers at Dolphins, Week 4 2019: who deserved to win?

The Chargers beat the Dolphins 30–10, and the replays back it up: with the way both teams actually played, the Chargers win 10 of 10. The Dolphins had the bounces: judgment calls alone were worth 13 points of win probability to the Dolphins.

Before kickoff the Chargers were 87% favorites. The biggest swing (Q2, 9:03 left): Offensive Pass Interference on the Chargers (Keenan Allen), 10 yards, wiping out the play, worth 23 points of win probability to the Dolphins.

Final

Los Angeles Chargers 30
Miami Dolphins 10

September 29, 2019 · Hard Rock Stadium · Closing line: Chargers −15

Luck index +4 Chargers about even · −4 Dolphins

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 10, Dolphins win 0.

  1. 1 LAC 33 MIA 3
  2. 2 LAC 25 MIA 0
  3. 3 LAC 24 MIA 3
  4. 4 LAC 27 MIA 7
  5. 5 LAC 17 MIA 0
  6. 6 LAC 24 MIA 10
  7. 7 LAC 17 MIA 6
  8. 8 LAC 23 MIA 14
  9. 9 LAC 24 MIA 17
  10. 10 LAC 16 MIA 13

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 96% of them, Dolphins 4%. The line is what actually happened: Chargers by 20.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+61.8%
Chargers by 9–1624.3%
Chargers by 1–89.9%
Level after regulation0.4%
Dolphins by 1–83.0%
Dolphins by 9–160.4%
Dolphins by 17+0.1%

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 +4.0 points to the Chargers: the final margin was Chargers by 20, without the luck Chargers by 15.9. 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.

  • T. Long, 44 yds made · 78% expected
  • J. Sanders, 30 yds made · 95% expected
  • J. Sanders, 50 yds missed · 64% expected
  • J. Sanders, 52 yds missed · 61% expected
  • T. Long, 45 yds made · 76% expected
  • T. Long, 51 yds made · 63% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Chargers 10 for 89 yards, Dolphins 5 for 53 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 12:18 Offensive Holding on the Chargers, 10 yards +2% MIA +0.9 pts
Q1 10:17 Delay of Game on the Chargers, 5 yards · pre-snap +1% MIA +0.4 pts
Q1 9:37 Illegal Formation on the Dolphins, 5 yards, wiping out the play · pre-snap +9% LAC +2.6 pts
Q1 6:02 Lowering the Head to Initiate Contact on the Dolphins (Eric Rowe), 15 yards +5% LAC +1.6 pts
Q1 1:32 Illegal Contact on the Chargers (Thomas Davis), 5 yards +2% MIA +0.5 pts
Q2 13:46 Offensive Holding on the Dolphins, 10 yards, wiping out the play +6% LAC +2.0 pts
Q2 12:52 Defensive Offside on the Chargers (Denzel Perryman), 5 yards · pre-snap +2% MIA +0.7 pts
Q2 12:04 Defensive Pass Interference on the Chargers, 10 yards +2% MIA +1.0 pts
Q2 11:10 Illegal Block Above the Waist on the Chargers (Geremy Davis), 8 yards +2% MIA +0.7 pts
Q2 9:03 Offensive Pass Interference on the Chargers (Keenan Allen), 10 yards, wiping out the play +23% MIA +6.6 pts
Q2 8:07 Unnecessary Roughness on the Dolphins (Christian Wilkins), 15 yards +7% LAC +1.8 pts
Q2 6:10 Face Mask on the Chargers, 15 yards +4% MIA +1.4 pts
Q3 9:46 Illegal Blindside Block on the Chargers (Keenan Allen), 11 yards, wiping out the play +7% MIA +1.9 pts
Q3 1:22 Offensive Holding on the Dolphins (Durham Smythe), 8 yards +1% LAC +0.7 pts
Q4 15:00 Offensive Holding on the Chargers, 10 yards +2% MIA +0.9 pts

Chargers penalties, every game · Dolphins penalties, every game · All teams, 2019

When it happened

Dolphins’ chance of winning

As low as 0% and as high as 70%. 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 Dolphins were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:37 Illegal Formation on the Dolphins, 5 yards, wiping out the playPre-snap flags +9% LAC LAC: Touchdown
2 Q2 9:03 Offensive Pass Interference on the Chargers (Keenan Allen), 10 yards, wiping out the playJudgment calls · 0 flags in 178 snaps before, position avg 1 per 331 +23% MIA MIA: Missed field goal
3 Q2 7:37 The Chargers fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +8% LAC LAC: Turnover on downs
4 Q2 6:10 The Chargers were stopped on 4th & 63rd & 4th downs · 43% expectedFace Mask on the Chargers, 15 yardsJudgment calls +11% MIA LAC: Touchdown
5 Q2 3:39 J. Sanders missed a 50-yard field goalKicks · 64% expected for him, 1 of 2 from 45+ before +7% LAC MIA: Missed field goal
6 Q2 1:02 The Chargers converted 3rd & 93rd & 4th downs · 34% expected +7% LAC LAC: Touchdown
7 Q2 0:03 J. Sanders missed a 52-yard field goalKicks · 61% expected for him, 1 of 3 from 45+ before +9% LAC MIA: Punt
8 Q3 9:46 Illegal Blindside Block on the Chargers (Keenan Allen), 11 yards, wiping out the playJudgment calls · 0 flags in 178 snaps before, position avg 1 per 331 +7% MIA MIA: Punt

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.

  • Jesse Davis (MIA T), out · 0.6 pts
  • Bobby McCain (MIA CB), out · 0.6 pts
  • Bobby McCain (MIA FS), out · 0.4 pts
  • Jesse Davis (MIA G), out · 0.3 pts
  • Danny Isidora (MIA G), out (IR) · 0.2 pts
  • Derwin James (LAC FS), out (IR) · 0.7 pts
  • Mike Williams (LAC WR), out · 0.7 pts
  • Hunter Henry (LAC TE), out · 0.6 pts
  • Adrian Phillips (LAC SS), out (IR) · 0.3 pts
  • Virgil Green (LAC TE), out · 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 98% · Dolphins 2%

Final margin
Chargers by 20
Luck in points
4.0 for the Chargers
Luck-adjusted margin
Chargers by 16.0
Replay with same day's form
Chargers 96% · Dolphins 4% 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 (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 4 2019 games · Chargers · Dolphins

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