luckadjusted
NFL Week 9 · 2026

Week 1 2024 · September 8, 2024

Rams at Lions, Week 1 2024: who deserved to win?

The Lions beat the Rams 26–20, and the replays lean their way: with the same day's form, they win 8 of 10.

Before kickoff the Lions were 64% favorites. The biggest swing (Q4, 0:17 left): the Rams got away with an interception-worthy throw, worth 50 points of win probability to the Rams.

Final (OT)

Los Angeles Rams 20
Detroit Lions 26

September 8, 2024 · Ford Field · Closing line: Lions −5

Luck index +23 Lions about even · −23 Rams

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. Rams win 2, Lions win 8.

  1. 1 LA 38 DET 24
  2. 2 LA 13 DET 10
  3. 3 LA 21 DET 23
  4. 4 LA 3 DET 7
  5. 5 LA 31 DET 38
  6. 6 LA 24 DET 34
  7. 7 LA 21 DET 34
  8. 8 LA 13 DET 30
  9. 9 LA 13 DET 34
  10. 10 LA 7 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.

How 4,000 replays ended

Rams win 23% of them, Lions 77%, counting the 3% still level after regulation as half each. The line is what actually happened: Lions by 6.

Show as a table
Final margin in the replaysShare of replays
Rams by 17+2.6%
Rams by 9–166.5%
Rams by 1–812.8%
Level after regulation2.5%
Lions by 1–824.9%
Lions by 9–1621.0%
Lions by 17+29.7%

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 +2.9 points to the Lions: the final margin was Lions by 6, without the luck Lions by 3.1. 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.

  • J. Karty, 41 yds made · 88% expected
  • J. Bates, 25 yds made · 98% expected
  • J. Karty, 26 yds made · 98% expected
  • J. Bates, 32 yds made · 96% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Rams 6 for 50 yards, Lions 6 for 56 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 half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued

WhenFlagWin probability for
Q1 11:29 Offensive Holding on the Rams, 10 yards +1% DET +0.9 pts
Q1 5:58 False Start on the Rams, 5 yards · pre-snap +2% DET +0.5 pts
Q1 2:55 Illegal Use of Hands on the Rams, 5 yards +1% DET +0.9 pts
Q2 1:20 Defensive Offside on the Lions (Marcus Davenport), 5 yards · pre-snap +3% LA +0.6 pts
Q2 0:50 Roughing the Passer on the Lions (Aidan Hutchinson), 15 yards +3% LA +1.8 pts
Q3 3:40 Defensive Pass Interference on the Lions (Terrion Arnold), 9 yards +3% LA +2.2 pts
Q4 14:16 Defensive Pass Interference on the Lions (Terrion Arnold), 17 yards +9% LA +1.7 pts
Q4 13:28 Offensive Holding on the Rams, 10 yards, wiping out the play +13% DET +2.6 pts
Q4 11:52 False Start on the Lions, 5 yards · pre-snap +2% LA +0.6 pts
Q4 9:15 False Start on the Lions, 5 yards · pre-snap +2% LA +0.7 pts
Q4 2:31 False Start on the Rams, 5 yards · pre-snap +1% DET +0.4 pts
Q4 2:00 Unnecessary Roughness on the Rams (Kamren Kinchens), 15 yards +12% DET +1.8 pts

Rams penalties, every game · Lions penalties, every game · All teams, 2024

When it happened

Lions’ chance of winning

As low as 24% 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 Rams were.
#WhenWhat happenedWin probability forNext drive
1 Q2 14:56 The Lions converted 4th & 23rd & 4th downs · 64% expected +7% DET DET: Field goal
2 Q2 6:36 C. Kupp dropped a catchable passDrops · 6 drops on 152 catchable balls before this +12% DET LA: Turnover
3 Q4 14:16 Defensive Pass Interference on the Lions (Terrion Arnold), 17 yardsJudgment calls · no snap history yet +9% LA LA: Field goal
4 Q4 13:28 Offensive Holding on the Rams, 10 yards, wiping out the playJudgment calls +13% DET DET: Turnover
5 Q4 9:15 The Lions threw an interception-worthy pass, and it was pickedInterceptions · defenses catch 56% of interception-worthy throwsFalse Start on the Lions, 5 yardsPre-snap flags +6% LA DET: Punt
6 Q4 2:00 Unnecessary Roughness on the Rams (Kamren Kinchens), 15 yardsJudgment calls · no snap history yet +12% DET DET: Field goal
7 Q4 0:24 The Lions were stopped on 3rd & 53rd & 4th downs · 44% expected +14% LA DET: Field goal
8 Q4 0:17 The Rams got away with an interception-worthy throwInterceptions · defenses catch 56% of interception-worthy throws +50% LA LA: 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.

  • Ifeatu Melifonwu (DET CB), out · 0.4 pts
  • John Cominsky (DET DE), out (IR) · 0.2 pts
  • Rob Havenstein (LA T), out · 1.0 pts
  • Tyler Higbee (LA TE), out (IR) · 0.7 pts
  • Alaric Jackson (LA T), out (IR) · 0.6 pts
  • Derion Kendrick (LA CB), out (IR) · 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

Rams 17% · Lions 83%

Final margin
Lions by 6
Luck in points
2.9 for the Lions
Luck-adjusted margin
Lions by 3.1
Replay with same day's form
Rams 23% · Lions 77% unchanged: why
How much of each is luck?

0% treats it as skill, 100% as pure luck. The tick is our fit.

What counts

None by default: our tests measured no carryover after a lucky break. Slide it up to count a break for more than its own swing. 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 1 2024 games · Rams · Lions

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