luckadjusted

Week 1 2021 · September 12, 2021

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

Chargers at Washington, Week 1 2021: who deserved to win?

The Chargers beat Washington 20–16, and it was no fluke: replayed with the way both teams actually played, the Chargers win 9 of 10. Washington had the bounces: judgment calls alone were worth 4.1 points to Washington.

An off day for Washington: their defense played far below its usual level. In a fresh game against the Chargers they would win 55% of the time; with this day’s form, 11%. The numbers

Before kickoff Washington were 57% favorites. The biggest swing (Q4, 5:59 left): Illegal Use of Hands on the Chargers, 10 yards, wiping out the play, worth 19 points of win probability to the Washington.

Final

Los Angeles Chargers 20
Washington Football Team 16

September 12, 2021 · FedExField · Closing line: Washington −2.5

Luck index +11 Chargers about even · −11 Washington

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 9, Washington win 1.

  1. 1 LAC 42 WAS 14
  2. 2 LAC 27 WAS 6
  3. 3 LAC 31 WAS 13
  4. 4 LAC 24 WAS 10
  5. 5 LAC 19 WAS 7
  6. 6 LAC 16 WAS 6
  7. 7 LAC 27 WAS 20
  8. 8 LAC 31 WAS 26
  9. 9 LAC 24 WAS 21
  10. 10 LAC 7 WAS 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.

An off day for the Washington

Their defense played far below its usual level. In a fresh game against the Chargers they would win 55% of the time; with this day’s form, 11%.

44 points apart for the Washington: the gap is how differently this game went from what the two teams usually are.

UnitThis gameUsual levelBetter or worse than usual
Chargers offenseEPA per play gained +0.28 +0.11 better by 0.17
Chargers defenseEPA per play allowed +0.03 +0.12 better by 0.09
Washington offenseEPA per play gained +0.03 +0.07 worse by 0.04
Washington defenseEPA per play allowed +0.28 +0.10 worse by 0.18

EPA (expected points added) per play on competitive snaps, turnovers left out because they are valued as luck. Usual level: the team’s earlier games this season plus half of last season, pulled toward the league average. One team’s defense and the other team’s offense are the same snaps, so one game can’t fully say whose day it was; it shows how far this one was from both teams’ norms.

How 4,000 replays ended

Chargers win 89% of them, Washington 11%, counting the 2% 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+41.5%
Chargers by 9–1627.0%
Chargers by 1–819.9%
Level after regulation1.7%
Washington by 1–87.2%
Washington by 9–162.1%
Washington by 17+0.6%

Where the luck was

Take the luck out

The final margin was Chargers by 4. Remove the luck, one kind at a time, and it becomes Chargers by 0.4.

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.

  • D. Hopkins, 30 yds made · 96% expected
  • D. Hopkins, 43 yds made · 83% expected
  • T. Vizcaino, 33 yds made · 95% expected
  • T. Vizcaino, 27 yds made · 98% expected
  • D. Hopkins, 48 yds made · 75% expected
  • D. Hopkins, 51 yds missed · 70% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Washington’ chance of winning

As low as 0% and as high as 80%. 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 Washington were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q3 11:41 Washington converted 3rd & 63rd & 4th downs · 36% expected +15% WAS WAS: Touchdown
2 Q3 9:33 The Chargers converted 3rd & 103rd & 4th downs · 26% expected +14% LAC LAC: Turnover
3 Q4 12:58 The Chargers converted 3rd & 73rd & 4th downs · 33% expected +11% LAC LAC: Turnover
4 Q4 12:16 Washington fumbled and the Chargers recoveredFumble bounces · loose balls are close to 50/50 +15% LAC WAS: Punt
5 Q4 11:25 The Chargers converted 3rd & 33rd & 4th downs · 43% expected +10% LAC LAC: Touchdown
6 Q4 8:44 Low Block on Washington (Adam Humphries), 15 yardsJudgment calls · 0 flags in 662 snaps before, position avg 1 per 399 +11% LAC LAC: End of game
7 Q4 5:59 Illegal Use of Hands on the Chargers, 10 yards, wiping out the playJudgment calls +19% WAS –
8 Q4 5:29 The Chargers converted 3rd & 163rd & 4th downs · 20% expected +13% LAC LAC: End of game

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 52% · Washington 48%

Final margin
Chargers by 4
Luck in points
3.6 for the Chargers
Luck-adjusted margin
Chargers by 0.4
Replay with same day's form
Chargers 89% · Washington 11% 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 1 2021 games · Chargers · Washington

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