luckadjusted

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 it was no fluke: replayed with the way both teams actually played, the Chargers win 10 of 10. The Dolphins had the bounces: judgment calls alone were worth 8.3 points 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 22 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 34 MIA 3
  2. 2 LAC 24 MIA 0
  3. 3 LAC 21 MIA 0
  4. 4 LAC 21 MIA 3
  5. 5 LAC 28 MIA 13
  6. 6 LAC 20 MIA 7
  7. 7 LAC 23 MIA 13
  8. 8 LAC 28 MIA 21
  9. 9 LAC 14 MIA 9
  10. 10 LAC 10 MIA 7

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%, counting the 1% still level after regulation as half each. The line is what actually happened: Chargers by 20.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+62.7%
Chargers by 9–1623.4%
Chargers by 1–89.5%
Level after regulation0.5%
Dolphins by 1–83.4%
Dolphins by 9–160.4%
Dolphins by 17+0.1%

Where the luck was

Take the luck out

The final margin was Chargers by 20. Remove the luck, one kind at a time, and it becomes Chargers by 19.7.

Each row takes one kind of luck out of the margin. Color shows which team it helped. Luck shares are the fitted ones (how much of each component 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 · 77% expected
  • J. Sanders, 30 yds made · 95% expected
  • J. Sanders, 50 yds missed · 66% expected
  • J. Sanders, 52 yds missed · 61% expected
  • T. Long, 45 yds made · 76% expected
  • T. Long, 51 yds made · 65% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

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 Q1 8:31 The Dolphins converted 3rd & 23rd & 4th downs · 57% expected +8% MIA MIA: Touchdown
3 Q1 6:39 The Dolphins converted 3rd & 23rd & 4th downs · 57% expected +9% MIA MIA: Touchdown
4 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 +22% MIA MIA: Missed field goal
5 Q2 7:37 The Chargers fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +8% LAC LAC: Turnover on downs
6 Q2 6:10 The Chargers were stopped on 4th & 63rd & 4th downs · 41% expectedFace Mask on the Chargers, 15 yardsJudgment calls +13% MIA LAC: Touchdown
7 Q2 3:39 J. Sanders missed 50-yard field goalKicks · 66% expected for him, 1 of 2 from 45+ before +8% LAC MIA: Missed field goal
8 Q2 0:03 J. Sanders missed 52-yard field goalKicks · 61% expected for him, 1 of 3 from 45+ before +9% LAC 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
0.3 for the Chargers
Luck-adjusted margin
Chargers by 19.7
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

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 4 2019 games · Chargers · Dolphins

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