luckadjusted

Week 3 2023 · September 24, 2023

Chargers at Vikings, Week 3 2023: who deserved to win?

The Chargers beat the Vikings 28–24, but it was a coin flip: replayed with the way both teams played, the Chargers win 5 of 10. Luck ran their way: fumble bounces alone were worth 11 points of win probability to the Chargers.

Before kickoff it was a pick’em. The biggest swing (Q4, 0:12 left): the Vikings were intercepted on a well-placed throw, worth 36 points of win probability to the Chargers.

Final

Los Angeles Chargers 28
Minnesota Vikings 24

September 24, 2023 · U.S. Bank Stadium · Closing line: Vikings −1

Luck index +52 Chargers lucky · −52 Vikings

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 5, Vikings win 5.

  1. 1 LAC 40 MIN 16
  2. 2 LAC 41 MIN 27
  3. 3 LAC 24 MIN 16
  4. 4 LAC 30 MIN 26
  5. 5 LAC 35 MIN 33
  6. 6 LAC 17 MIN 19
  7. 7 LAC 13 MIN 19
  8. 8 LAC 13 MIN 23
  9. 9 LAC 13 MIN 28
  10. 10 LAC 6 MIN 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

Chargers win 48% of them, Vikings 52%, counting the 6% still level after regulation as half each. The line is what actually happened: Chargers by 4.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+10.7%
Chargers by 9–1613.9%
Chargers by 1–821.4%
Level after regulation5.7%
Vikings by 1–822.0%
Vikings by 9–1614.8%
Vikings by 17+11.7%

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 +7.2 points to the Vikings: the final margin was Chargers by 4, without the luck Chargers by 11.2. 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.

  • G. Joseph, 23 yds made · 99% expected
  • C. Dicker, 53 yds missed · 71% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Chargers 12 for 94 yards, Vikings 6 for 45 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 toward luck, pre-snap fouls mostly don’t. How calls are valued

WhenFlagWin probability for
Q1 14:28 Offensive Holding on the Chargers, 10 yards +3% MIN +1.5 pts
Q1 1:41 Neutral Zone Infraction on the Chargers, 5 yards · pre-snap +4% MIN +1.4 pts
Q2 8:32 Defensive Holding on the Chargers (Tuli Tuipulotu), 5 yards +1% MIN +0.2 pts
Q2 4:57 Intentional Grounding on the Vikings (Kirk Cousins), 10 yards +3% LAC +1.0 pts
Q2 4:54 Defensive Pass Interference on the Chargers (Michael Davis), 16 yards +6% MIN +2.0 pts
Q2 4:47 Offensive Holding on the Vikings, 10 yards, wiping out the play +5% LAC +1.8 pts
Q2 3:41 False Start on the Vikings, 5 yards · pre-snap +1% LAC +0.6 pts
Q2 3:37 Unnecessary Roughness on the Chargers (Derwin James), 3 yards +2% MIN +0.5 pts
Q3 13:05 False Start on the Chargers (Donald Parham), 5 yards · pre-snap +2% MIN +0.5 pts
Q3 9:19 False Start on the Vikings, 5 yards · pre-snap +3% LAC +0.6 pts
Q3 4:26 Defensive Holding on the Chargers (Michael Davis), 5 yards +1% MIN +0.9 pts
Q3 2:27 Offensive Holding on the Chargers (Tre' McKitty), 10 yards +3% MIN +0.8 pts
Q4 15:00 Offensive Holding on the Vikings, 10 yards, wiping out the play +6% LAC +1.7 pts
Q4 11:20 Defensive Offside on the Chargers (Asante Samuel Jr.), 5 yards · pre-snap +3% MIN +0.5 pts
Q4 9:53 Offensive Pass Interference on the Chargers (Keenan Allen), 10 yards, wiping out the play +24% MIN +2.9 pts
Q4 7:30 Unnecessary Roughness on the Chargers (Raheem Layne), 15 yards +10% MIN +1.9 pts
Q4 1:02 Illegal Use of Hands on the Chargers (Michael Davis), 5 yards +12% MIN +1.2 pts
Q4 0:55 Delay of Game on the Vikings, 5 yards · pre-snap +6% LAC +0.5 pts

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

When it happened

Vikings’ chance of winning

As low as 0% and as high as 75%. 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 Vikings were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 8:41 The Vikings were stopped on 3rd & 83rd & 4th downs · 31% expectedThe Vikings fumbled and the Chargers recoveredFumble bounces · loose balls are close to 50/50 +17% LAC MIN: Punt
2 Q2 0:50 The Chargers converted 4th & 13rd & 4th downs · 68% expected +15% LAC LAC: Touchdown
3 Q3 3:09 The Vikings converted 4th & 63rd & 4th downs · 36% expected +19% MIN MIN: Touchdown
4 Q4 9:53 Offensive Pass Interference on the Chargers (Keenan Allen), 10 yards, wiping out the playJudgment calls · 8 flags in 3500 snaps before, position avg 1 per 420 +24% MIN MIN: Turnover on downs
5 Q4 8:51 The Chargers converted 3rd & 173rd & 4th downs · 20% expected +16% LAC LAC: Touchdown
6 Q4 2:58 The Vikings were stopped on 4th & 23rd & 4th downs · 51% expected +21% LAC MIN: Turnover
7 Q4 1:51 The Chargers were stopped on 4th & 13rd & 4th downs · 75% expected +31% MIN LAC: End of game
8 Q4 0:12 The Vikings were intercepted on a well-placed throwInterceptions · 0% expected to stay out of the defense's hands +36% LAC –

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.

  • Garrett Bradbury (MIN C), out · 0.3 pts
  • J.C. Jackson (LAC CB), out · 0.4 pts
  • Austin Ekeler (LAC RB), 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 91% · Vikings 9%

Final margin
Chargers by 4
Luck in points
7.2 for the Vikings
Luck-adjusted margin
Chargers by 11.2
Replay with same day's form
Chargers 48% · Vikings 52% 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 3 2023 games · Chargers · Vikings

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