luckadjusted

Week 4 2024 · September 30, 2024

Seahawks at Lions, Week 4 2024: who deserved to win?

The Lions beat the Seahawks 42–29 and were the better team on the day: replayed with the same form, they win 8 of 10.

Before kickoff the Lions were 60% favorites. The biggest swing (Q1, 1:06 left): the Seahawks fumbled and the Lions recovered, worth 8 points of win probability to the Lions.

Final

Seattle Seahawks 29
Detroit Lions 42

September 30, 2024 · Ford Field · Closing line: Lions −3.5

Luck index +21 Lions about even · −21 Seahawks

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. Seahawks win 2, Lions win 8.

  1. 1 SEA 31 DET 19
  2. 2 SEA 34 DET 31
  3. 3 SEA 27 DET 29
  4. 4 SEA 21 DET 26
  5. 5 SEA 27 DET 36
  6. 6 SEA 7 DET 20
  7. 7 SEA 17 DET 33
  8. 8 SEA 7 DET 27
  9. 9 SEA 10 DET 37
  10. 10 SEA 10 DET 44

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

Seahawks win 21% of them, Lions 79%, counting the 1% still level after regulation as half each. The line is what actually happened: Lions by 13.

Show as a table
Final margin in the replaysShare of replays
Seahawks by 17+2.6%
Seahawks by 9–166.7%
Seahawks by 1–811.3%
Level after regulation1.3%
Lions by 1–821.7%
Lions by 9–1622.0%
Lions by 17+34.5%

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 +1.9 points to the Lions: the final margin was Lions by 13, without the luck Lions by 11.1. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Seahawks 8 for 70 yards, Lions 12 for 101 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 12:54 Offensive Holding on the Seahawks (Tre Brown), 10 yards +3% DET +0.7 pts
Q2 12:50 Defensive Holding on the Lions (Carlton Davis), 5 yards +3% SEA +1.2 pts
Q2 10:42 Defensive Too Many Men on Field on the Lions, 0 yards · pre-snap 0% SEA 0.0 pts
Q2 9:47 Face Mask on the Seahawks (Trevis Gipson), 15 yards +4% DET +1.9 pts
Q2 5:33 Defensive Too Many Men on Field on the Seahawks, 0 yards · pre-snap 0% DET 0.0 pts
Q2 2:00 Offensive Holding on the Seahawks (Pharaoh Brown), 10 yards +1% DET +0.5 pts
Q2 1:01 Offensive Holding on the Lions, 7 yards +1% SEA +0.4 pts
Q3 9:57 Defensive Pass Interference on the Lions (Carlton Davis), 21 yards +3% SEA +1.0 pts
Q3 3:53 Defensive Holding on the Lions (Terrion Arnold), 5 yards 0% SEA +0.2 pts
Q3 3:03 Defensive Pass Interference on the Lions (Carlton Davis), 1 yard 0% SEA 0.0 pts
Q3 3:03 Unsportsmanlike Conduct on the Lions (Jameson Williams), 15 yards +2% SEA +1.7 pts
Q4 10:28 Offensive Holding on the Seahawks (D.K. Metcalf), 10 yards +3% DET +0.6 pts
Q4 9:18 Offensive Pass Interference on the Seahawks (Tyler Lockett), 10 yards, wiping out the play +6% DET +2.0 pts
Q4 9:02 False Start on the Seahawks (Zach Charbonnet), 5 yards · pre-snap 0% DET +0.2 pts
Q4 6:17 Offensive Pass Interference on the Lions (Brock Wright), 10 yards +1% SEA +1.3 pts
Q4 2:54 Defensive Offside on the Lions (James Houston), 5 yards · pre-snap 0% DET +0.7 pts
Q4 2:40 Defensive Holding on the Lions (Terrion Arnold), 4 yards 0% SEA +0.6 pts
Q4 2:01 Offensive Holding on the Seahawks (Dareke Young), 10 yards 0% DET +0.8 pts
Q4 1:16 Defensive Pass Interference on the Lions (Terrion Arnold), 13 yards 0% SEA +0.8 pts
Q4 1:11 Roughing the Passer on the Lions (Levi Onwuzurike), 15 yards 0% SEA +1.6 pts

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

When it happened

Lions’ chance of winning

As low as 45% 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 Seahawks were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:35 The Lions were stopped on 3rd & 63rd & 4th downs · 42% expected +7% SEA DET: Punt
2 Q1 2:28 The Seahawks converted 3rd & 83rd & 4th downs · 30% expected +5% SEA SEA: Turnover
3 Q1 1:06 The Seahawks fumbled and the Lions recoveredFumble bounces · loose balls are close to 50/50 +8% DET SEA: Touchdown
4 Q2 9:47 Face Mask on the Seahawks (Trevis Gipson), 15 yardsJudgment calls · 3 flags in 1547 snaps before, position avg 1 per 445 +4% DET DET: Touchdown
5 Q2 3:12 The Seahawks converted 3rd & 163rd & 4th downs · 19% expected +5% SEA SEA: Punt
6 Q4 13:32 The Lions were stopped on 3rd & 13rd & 4th downs · 78% expected +4% SEA DET: Punt
7 Q4 9:21 The Seahawks were stopped on 3rd & 33rd & 4th downs · 51% expected +4% DET SEA: Punt
8 Q4 9:18 Offensive Pass Interference on the Seahawks (Tyler Lockett), 10 yards, wiping out the playJudgment calls · 9 flags in 4880 snaps before, position avg 1 per 409 +6% DET DET: Touchdown

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.

  • Frank Ragnow (DET C), out · 0.8 pts
  • Brian Branch (DET SS), out · 0.6 pts
  • Ifeatu Melifonwu (DET CB), out (IR) · 0.3 pts
  • John Cominsky (DET DE), out (IR) · 0.2 pts
  • Derrick Barnes (DET LB), out (IR) · 0.2 pts
  • Marcus Davenport (DET LB), out (IR) · 0.2 pts
  • Abraham Lucas (SEA T), out (IR) · 0.8 pts
  • Leonard Williams (SEA DT), out · 0.6 pts
  • Jerome Baker (SEA LB), out · 0.3 pts
  • Boye Mafe (SEA 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

Seahawks 4% · Lions 96%

Final margin
Lions by 13
Luck in points
2.0 for the Lions
Luck-adjusted margin
Lions by 11.0
Replay with same day's form
Seahawks 21% · Lions 79% 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 4 2024 games · Seahawks · Lions

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