luckadjusted

Week 14 2023 · December 10, 2023

Seahawks at 49ers, Week 14 2023: who deserved to win?

The 49ers beat the Seahawks 28–16, and it was no fluke: replayed with the way both teams actually played, the 49ers win 10 of 10. The Seahawks had the bounces: fumble bounces alone were worth 1.6 points to the Seahawks.

Before kickoff the 49ers were 86% favorites. The biggest swing (Q2, 8:26 left): the 49ers converted 3rd & 11, worth 22 points of win probability to the 49ers.

Final

Seattle Seahawks 16
San Francisco 49ers 28

December 10, 2023 · Levi's Stadium · Closing line: 49ers −14.5

Luck index +3 49ers about even · −3 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 0, 49ers win 10.

  1. 1 SEA 17 SF 20
  2. 2 SEA 27 SF 34
  3. 3 SEA 13 SF 24
  4. 4 SEA 31 SF 45
  5. 5 SEA 24 SF 41
  6. 6 SEA 21 SF 42
  7. 7 SEA 13 SF 38
  8. 8 SEA 17 SF 47
  9. 9 SEA 9 SF 44
  10. 10 SEA 6 SF 51

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 3% of them, 49ers 97%, counting the 1% still level after regulation as half each. The line is what actually happened: 49ers by 12.

Show as a table
Final margin in the replaysShare of replays
Seahawks by 17+0.1%
Seahawks by 9–160.4%
Seahawks by 1–81.7%
Level after regulation0.5%
49ers by 1–86.4%
49ers by 9–1613.1%
49ers by 17+77.7%

Where the luck was

Take the luck out

The final margin was 49ers by 12. Remove the luck, one kind at a time, and it becomes 49ers by 8.7.

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).

When it happened

49ers’ chance of winning

As low as 32% 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 49ers were ahead in it, below while the Seahawks were.
#WhenWhat happenedWin probability forNext drive
1 Q1 10:24 The Seahawks converted 3rd & 63rd & 4th downs · 35% expected +6% SEA SEA: Touchdown
2 Q1 2:01 K. Walker dropped a catchable passDrops · 2 drops on 48 catchable balls before this +5% SF SEA: Field goal
3 Q2 14:24 The 49ers were intercepted on a well-placed throwInterceptions · 0% expected to stay out of the defense's hands +12% SEA SF: Touchdown
4 Q2 8:26 The 49ers converted 3rd & 113rd & 4th downs · 29% expected +22% SF SF: Touchdown
5 Q3 14:51 The Seahawks got away with an interception-worthy throwInterceptions · 49% expected to stay out of the defense's hands +7% SEA SEA: Punt
6 Q3 11:16 The 49ers were stopped on 3rd & 63rd & 4th downs · 40% expected +6% SEA SF: Punt
7 Q3 8:42 The Seahawks converted 3rd & 83rd & 4th downs · 29% expected +7% SEA SEA: Punt
8 Q4 5:25 Defensive Offside on the 49ers (Nick Bosa), 5 yards, wiping out the playPre-snap flags · 11 flags in 3526 snaps before, position avg 1 per 295 +10% SEA SEA: Turnover

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.

  • Talanoa Hufanga (SF SS), out (IR) · 0.6 pts
  • Spencer Burford (SF G), out · 0.3 pts
  • Arik Armstead (SF DT), out · 0.3 pts
  • Geno Smith (SEA QB), out, replaced by d.lock · 3.7 pts
  • Tre Brown (SEA CB), out · 0.3 pts
  • Phil Haynes (SEA G), out (IR) · 0.2 pts
  • Uchenna Nwosu (SEA LB), out (IR) · 0.2 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 0% · 49ers 100%

Final margin
49ers by 12
Luck in points
3.4 for the 49ers
Luck-adjusted margin
49ers by 8.6
Replay with same day's form
Seahawks 3% · 49ers 97% 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 14 2023 games · Seahawks · 49ers

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