luckadjusted

Week 18 2024 · January 5, 2025

Seahawks at Rams, Week 18 2024: who deserved to win?

The Seahawks beat the Rams 30–25, but it was a coin flip: replayed with the way both teams played, the Seahawks win 4 of 10. Luck ran their way: 3rd & 4th downs alone were worth 17 points of win probability to the Seahawks.

Before kickoff the Seahawks were 71% favorites. The biggest swing (Q4, 0:21 left): the Rams were stopped on 4th & 3, worth 33 points of win probability to the Seahawks.

Final

Seattle Seahawks 30
Los Angeles Rams 25

January 5, 2025 · SoFi Stadium · Closing line: Seahawks −7.5

Luck index +58 Seahawks lucky · −58 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. Seahawks win 4, Rams win 6.

  1. 1 SEA 31 LA 10
  2. 2 SEA 24 LA 13
  3. 3 SEA 33 LA 28
  4. 4 SEA 15 LA 13
  5. 5 SEA 14 LA 16
  6. 6 SEA 26 LA 30
  7. 7 SEA 24 LA 31
  8. 8 SEA 13 LA 23
  9. 9 SEA 16 LA 30
  10. 10 SEA 13 LA 36

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 42% of them, Rams 58%, counting the 3% still level after regulation as half each. The line is what actually happened: Seahawks by 5.

Show as a table
Final margin in the replaysShare of replays
Seahawks by 17+6.8%
Seahawks by 9–1612.8%
Seahawks by 1–820.1%
Level after regulation3.0%
Rams by 1–828.9%
Rams by 9–1615.7%
Rams by 17+12.7%

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 +4.2 points to the Seahawks: the final margin was Seahawks by 5, without the luck Seahawks by 0.8. 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, 37 yds made · 92% expected
  • J. Myers, 56 yds made · 67% expected
  • J. Karty, 58 yds made · 63% expected
  • J. Karty, 57 yds made · 65% expected
  • J. Karty, 38 yds made · 91% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Seahawks 3 for 23 yards, Rams 2 for 10 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 13:37 False Start on the Rams, 5 yards · pre-snap +1% SEA +0.7 pts
Q1 7:10 False Start on the Seahawks (Jake Bobo), 5 yards · pre-snap +3% LA +0.7 pts
Q2 9:55 Face Mask on the Seahawks (Tre Brown), 13 yards +4% LA +1.1 pts
Q2 1:21 False Start on the Seahawks, 5 yards · pre-snap +1% LA +0.9 pts
Q4 6:49 Defensive Offside on the Rams, 5 yards, wiping out the play · pre-snap +20% SEA +2.7 pts

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

When it happened

Rams’ chance of winning

As low as 0% and as high as 63%. 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 Rams were ahead in it, below while the Seahawks were.
#WhenWhat happenedWin probability forNext drive
1 Q1 8:48 The Rams were stopped on 3rd & 53rd & 4th downs · 41% expectedT. Atwell dropped a catchable passDrops · 5 drops on 108 catchable balls before this +10% SEA LA: Punt
2 Q2 2:27 The Rams were stopped on 3rd & 73rd & 4th downs · 34% expectedThe Rams threw an interception-worthy pass, and it was pickedInterceptions · 51% expected to stay out of the defense's hands +14% SEA LA: Field goal
3 Q3 8:42 The Rams were stopped on 3rd & 13rd & 4th downs · 73% expected +12% SEA LA: Field goal
4 Q3 7:42 The Seahawks converted 3rd & 103rd & 4th downs · 27% expected +12% SEA SEA: Touchdown
5 Q4 9:49 The Rams converted 3rd & 43rd & 4th downs · 46% expected +21% LA LA: Field goal
6 Q4 6:49 Defensive Offside on the Rams, 5 yards, wiping out the playPre-snap flags +20% SEA SEA: Touchdown
7 Q4 2:35 The Rams converted 4th & 63rd & 4th downs · 37% expected +12% LA LA: Turnover on downs
8 Q4 0:21 The Rams were stopped on 4th & 33rd & 4th downs · 43% expected +33% SEA –

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.

  • Puka Nacua (LA WR), out · 1.4 pts
  • Cooper Kupp (LA WR), out · 1.1 pts
  • Rob Havenstein (LA T), out · 1.0 pts
  • Alaric Jackson (LA T), out · 0.6 pts
  • Kyren Williams (LA RB), out · 0.5 pts
  • Kevin Dotson (LA G), out · 0.4 pts
  • Matthew Stafford (LA QB), out, replaced by j.garoppolo · 0.4 pts
  • Abraham Lucas (SEA T), out (IR) · 0.8 pts
  • Josh Jobe (SEA CB), out (IR) · 0.4 pts
  • Kenneth Walker III (SEA RB), out (IR) · 0.3 pts
  • Anthony Bradford (SEA G), 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

Seahawks 81% · Rams 19%

Final margin
Seahawks by 5
Luck in points
4.2 for the Seahawks
Luck-adjusted margin
Seahawks by 0.8
Replay with same day's form
Seahawks 42% · Rams 58% 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 18 2024 games · Seahawks · Rams

More from Week 18 2024