luckadjusted

Week 3 2023 · September 24, 2023

Falcons at Lions, Week 3 2023: who deserved to win?

The Lions beat the Falcons 20–6, and it was no fluke: replayed with the way both teams actually played, the Lions win 10 of 10. The Falcons had the bounces: judgment calls alone were worth 8.4 points to the Falcons.

An off day for the Falcons: their offense played far below its usual level. In a fresh game against the Lions they would win 33% of the time; with this day’s form, 2%. The numbers

Before kickoff the Lions were 59% favorites. The biggest swing (Q3, 0:10 left): the Lions were stopped on 3rd & 10, worth 8 points of win probability to the Falcons.

Final

Atlanta Falcons 6
Detroit Lions 20

September 24, 2023 · Ford Field · Closing line: Lions −3

Luck index +2 Lions about even · −2 Falcons

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. Falcons win 0, Lions win 10.

  1. 1 ATL 27 DET 30
  2. 2 ATL 27 DET 34
  3. 3 ATL 23 DET 33
  4. 4 ATL 30 DET 43
  5. 5 ATL 3 DET 19
  6. 6 ATL 16 DET 35
  7. 7 ATL 7 DET 28
  8. 8 ATL 9 DET 34
  9. 9 ATL 13 DET 43
  10. 10 ATL 0 DET 37

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 Falcons

Their offense played far below its usual level. In a fresh game against the Lions they would win 33% of the time; with this day’s form, 2%.

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

UnitThis gameUsual levelBetter or worse than usual
Falcons offenseEPA per play gained −0.39 +0.09 worse by 0.48
Falcons defenseEPA per play allowed +0.02 +0.12 better by 0.10
Lions offenseEPA per play gained +0.02 +0.13 worse by 0.11
Lions defenseEPA per play allowed −0.39 +0.15 better by 0.53

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

Falcons win 2% of them, Lions 98%. The line is what actually happened: Lions by 14.

Show as a table
Final margin in the replaysShare of replays
Falcons by 17+0.1%
Falcons by 9–160.3%
Falcons by 1–81.9%
Level after regulation0.4%
Lions by 1–85.4%
Lions by 9–1614.7%
Lions by 17+77.2%

Where the luck was

Take the luck out

The final margin was Lions by 14. Remove the luck, one kind at a time, and it becomes Lions by 23.2.

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.

  • R. Patterson, 37 yds made · 92% expected
  • Y. Koo, 48 yds made · 83% expected
  • R. Patterson, 24 yds made · 99% expected
  • Y. Koo, 47 yds missed · 85% expected
  • Y. Koo, 24 yds made · 100% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Lions’ chance of winning

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 Falcons were.
#WhenWhat happenedWin probability forNext drive
1 Q1 11:07 The Falcons converted 3rd & 73rd & 4th downs · 31% expected +8% ATL ATL: Punt
2 Q2 11:41 The Falcons were stopped on 3rd & 143rd & 4th downs · 20% expected +4% DET ATL: Field goal
3 Q2 11:37 Y. Koo made 48-yard field goalKicks · 83% expected for him, 38 of 45 from 45+ before +5% ATL ATL: Punt
4 Q2 10:45 The Lions converted 3rd & 83rd & 4th downs · 31% expected +8% DET DET: Touchdown
5 Q3 9:12 The Falcons were stopped on 3rd & 63rd & 4th downs · 34% expected +4% DET ATL: Missed field goal
6 Q3 8:30 Y. Koo missed 47-yard field goalKicks · 85% expected for him, 39 of 46 from 45+ before +6% DET ATL: Punt
7 Q3 0:10 The Lions were stopped on 3rd & 103rd & 4th downs · 27% expectedThe Lions threw an interception-worthy pass, and it was pickedInterceptions · 47% expected to stay out of the defense's hands +8% ATL DET: Touchdown
8 Q4 13:50 The Falcons were stopped on 3rd & 43rd & 4th downs · 42% expected +5% DET ATL: Turnover on downs

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
  • Kerby Joseph (DET SS), out · 0.9 pts
  • Kerby Joseph (DET FS), out · 0.8 pts
  • David Montgomery (DET RB), out · 0.4 pts
  • Halapoulivaati Vaitai (DET G), out · 0.2 pts
  • Matt Hennessy (ATL C), out (IR) · 0.2 pts
  • Adetokunbo Ogundeji (ATL LB), out (IR) · 0.1 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

Falcons 0% · Lions 100%

Final margin
Lions by 14
Luck in points
9.2 for the Falcons
Luck-adjusted margin
Lions by 23.2
Replay with same day's form
Falcons 2% · Lions 98% 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 · Falcons · Lions

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