luckadjusted

Week 2 2019 · September 15, 2019

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

Chargers at Lions, Week 2 2019: who deserved to win?

The Lions beat the Chargers 13–10, but the Chargers played well enough to win it: they take 7 of 10 replays with the same day's form. Luck ran their way: kicks alone were worth 2.1 points to the Lions.

Before kickoff it was a pick’em. The biggest swing (Q4, 1:10 left): the Chargers were stopped on 3rd & 19, worth 41 points of win probability to the Lions.

Final

Los Angeles Chargers 10
Detroit Lions 13

September 15, 2019 · Ford Field · Closing line: Chargers −1

Luck index +72 Lions very lucky · −72 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 7, Lions win 3.

  1. 1 LAC 34 DET 7
  2. 2 LAC 41 DET 22
  3. 3 LAC 34 DET 20
  4. 4 LAC 45 DET 34
  5. 5 LAC 23 DET 16
  6. 6 LAC 13 DET 9
  7. 7 LAC 36 DET 34
  8. 8 LAC 14 DET 17
  9. 9 LAC 21 DET 30
  10. 10 LAC 13 DET 31

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 72% of them, Lions 28%, counting the 5% still level after regulation as half each. The line is what actually happened: Lions by 3.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+25.4%
Chargers by 9–1621.0%
Chargers by 1–822.9%
Level after regulation4.7%
Lions by 1–815.2%
Lions by 9–166.8%
Lions by 17+4.0%

Where the luck was

Take the luck out

The final margin was Lions by 3. Remove the luck, one kind at a time, and it becomes Lions by 1.2.

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.

  • M. Prater, 40 yds missed · 89% expected
  • T. Long, 39 yds made · 90% expected
  • T. Long, 39 yds missed · 90% expected
  • T. Long, 41 yds missed · 87% expected
  • Extra point missed · 95% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Lions’ chance of winning

As low as 18% 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 Lions were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q2 6:02 M. Prater missed 40-yard field goalKicks · 89% expected for him +16% LAC DET: Punt
2 Q3 8:32 The Chargers fumbled and the Lions recoveredFumble bounces · loose balls are close to 50/50 +9% DET LAC: Missed field goal
3 Q3 2:13 T. Long missed 39-yard field goalKicks · 90% expected for him +10% DET LAC: Missed field goal
4 Q4 15:00 The Chargers converted 3rd & 33rd & 4th downs · 52% expected +9% LAC LAC: Missed field goal
5 Q4 11:50 T. Long missed 41-yard field goalKicks · 87% expected for him +16% DET LAC: Turnover
6 Q4 8:06 The Lions converted 4th & 13rd & 4th downs · 72% expected +12% DET DET: Touchdown
7 Q4 3:23 The Chargers converted 3rd & 53rd & 4th downs · 42% expected +13% LAC LAC: Turnover
8 Q4 1:10 The Chargers were stopped on 3rd & 193rd & 4th downs · 19% expectedDelay of Game on the Chargers, 5 yardsPre-snap flags +41% DET LAC: End of game

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.

  • Taylor Decker (DET T), out · 1.1 pts
  • Jarrad Davis (DET LB), out · 0.3 pts
  • Da'Shawn Hand (DET DE), out · 0.2 pts
  • Derwin James (LAC FS), out (IR) · 0.7 pts
  • Michael Davis (LAC CB), out · 0.6 pts
  • Hunter Henry (LAC TE), out · 0.6 pts
  • Jatavis Brown (LAC LB), out · 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 38% · Lions 62%

Final margin
Lions by 3
Luck in points
1.8 for the Lions
Luck-adjusted margin
Lions by 1.2
Replay with same day's form
Chargers 72% · Lions 28% 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 2 2019 games · Chargers · Lions

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