luckadjusted

Week 8 2020 · November 1, 2020

No FTN charting for this game (drops and interception-worthy throws are not modelled).

49ers at Seahawks, Week 8 2020: who deserved to win?

The Seahawks beat the 49ers 37–27, but it was a coin flip: replayed with the way both teams played, the Seahawks win 6 of 10. Luck ran their way: 3rd & 4th downs alone were worth 2.6 points to the Seahawks.

Before kickoff it was a pick’em. The biggest swing (Q1, 4:13 left): the 49ers were stopped on 3rd & 5, worth 14 points of win probability to the Seahawks.

Final

San Francisco 49ers 27
Seattle Seahawks 37

November 1, 2020 · CenturyLink Field · Closing line: Seahawks −1

Luck index +41 Seahawks lucky · −41 49ers

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. 49ers win 4, Seahawks win 6.

  1. 1 SF 42 SEA 21
  2. 2 SF 38 SEA 26
  3. 3 SF 30 SEA 24
  4. 4 SF 20 SEA 17
  5. 5 SF 35 SEA 37
  6. 6 SF 13 SEA 17
  7. 7 SF 16 SEA 24
  8. 8 SF 24 SEA 36
  9. 9 SF 23 SEA 41
  10. 10 SF 23 SEA 49

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

49ers win 41% of them, Seahawks 59%, counting the 3% still level after regulation as half each. The line is what actually happened: Seahawks by 10.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+8.3%
49ers by 9–1612.2%
49ers by 1–819.3%
Level after regulation2.7%
Seahawks by 1–825.4%
Seahawks by 9–1616.6%
Seahawks by 17+15.6%

Where the luck was

Take the luck out

The final margin was Seahawks by 10. Remove the luck, one kind at a time, and it becomes Seahawks by 4.4.

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.

  • J. Myers, 48 yds made · 74% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Seahawks’ chance of winning

As low as 38% 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 Seahawks were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 11:12 The 49ers were stopped on 3rd & 53rd & 4th downs · 44% expected +6% SEA SF: Punt
2 Q1 9:38 The Seahawks converted 3rd & 53rd & 4th downs · 40% expected +7% SEA SEA: Punt
3 Q1 4:13 The 49ers were stopped on 3rd & 53rd & 4th downs · 44% expected +14% SEA SF: Touchdown
4 Q2 11:30 The 49ers converted 4th & 13rd & 4th downs · 76% expected +7% SF SF: Touchdown
5 Q2 9:00 The 49ers converted 3rd & 93rd & 4th downs · 32% expected +6% SF SF: Touchdown
6 Q2 7:03 The 49ers converted 3rd & 13rd & 4th downs · 69% expected +6% SF SF: Touchdown
7 Q3 14:20 The 49ers fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +7% SF SF: Punt
8 Q3 13:44 The 49ers were stopped on 3rd & 43rd & 4th downs · 49% expected +7% SEA SF: Punt

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.

  • Shaquill Griffin (SEA CB), out · 0.7 pts
  • Jamal Adams (SEA SS), out · 0.6 pts
  • Mike Iupati (SEA G), out · 0.5 pts
  • Benson Mayowa (SEA DE), out · 0.4 pts
  • Chris Carson (SEA RB), out · 0.3 pts
  • Bruce Irvin (SEA LB), out (IR) · 0.3 pts
  • Deebo Samuel (SF WR), out · 1.1 pts
  • Nick Bosa (SF DE), out (IR) · 1.0 pts
  • Ben Garland (SF OL), out (IR) · 0.4 pts
  • Kwon Alexander (SF LB), out · 0.4 pts
  • Jaquiski Tartt (SF S), out · 0.4 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

49ers 14% · Seahawks 86%

Final margin
Seahawks by 10
Luck in points
5.6 for the Seahawks
Luck-adjusted margin
Seahawks by 4.4
Replay with same day's form
49ers 41% · Seahawks 59% 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 (not available for this game); injuries from snap counts and injury reports. No FTN charting for this game (drops and interception-worthy throws are not modelled).

Methodology and validation · All Week 8 2020 games · 49ers · Seahawks

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