luckadjusted

Week 4 2020 · October 4, 2020

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

Seahawks at Dolphins, Week 4 2020: who deserved to win?

The Seahawks beat the Dolphins 31–23, and it was no fluke: replayed with the way both teams actually played, the Seahawks win 8 of 10. The Dolphins had the bounces: kicks alone were worth 8 points of win probability to the Dolphins.

Before kickoff the Seahawks were 63% favorites. The biggest swing (Q4, 9:18 left): the Dolphins were stopped on 3rd & 3, worth 16 points of win probability to the Seahawks.

Final

Seattle Seahawks 31
Miami Dolphins 23

October 4, 2020 · Hard Rock Stadium · Closing line: Seahawks −4.5

Luck index +18 Seahawks about even · −18 Dolphins

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 8, Dolphins win 2.

  1. 1 SEA 39 MIA 10
  2. 2 SEA 33 MIA 10
  3. 3 SEA 38 MIA 19
  4. 4 SEA 31 MIA 16
  5. 5 SEA 33 MIA 21
  6. 6 SEA 30 MIA 20
  7. 7 SEA 23 MIA 17
  8. 8 SEA 40 MIA 38
  9. 9 SEA 34 MIA 37
  10. 10 SEA 16 MIA 29

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 82% of them, Dolphins 18%, counting the 1% still level after regulation as half each. The line is what actually happened: Seahawks by 8.

Show as a table
Final margin in the replaysShare of replays
Seahawks by 17+35.3%
Seahawks by 9–1622.5%
Seahawks by 1–823.7%
Level after regulation1.1%
Dolphins by 1–810.6%
Dolphins by 9–164.9%
Dolphins by 17+1.8%

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 +1.5 points to the Dolphins: the final margin was Seahawks by 8, without the luck Seahawks by 9.5. 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. Sanders, 41 yds made · 83% expected
  • J. Myers, 55 yds made · 56% expected
  • J. Sanders, 29 yds made · 96% expected
  • J. Sanders, 45 yds made · 76% expected
  • J. Sanders, 43 yds made · 80% expected
  • J. Sanders, 29 yds made · 96% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Seahawks 0 for 0 yards, Dolphins 3 for 20 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 8:45 Illegal Forward Pass on the Dolphins (Ryan Fitzpatrick), 5 yards +1% SEA +0.6 pts
Q1 3:59 Offensive Holding on the Dolphins, 10 yards, wiping out the play +5% SEA +1.8 pts
Q3 10:16 Illegal Contact on the Dolphins, 5 yards +1% SEA +1.0 pts

Seahawks penalties, every game · Dolphins penalties, every game · All teams, 2020

When it happened

Dolphins’ chance of winning

As low as 0% and as high as 58%. 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 Dolphins were ahead in it, below while the Seahawks were.
#WhenWhat happenedWin probability forNext drive
1 Q2 4:52 The Seahawks were stopped on 4th & 33rd & 4th downs · 55% expected +12% MIA SEA: Touchdown
2 Q3 10:00 The Seahawks were stopped on 3rd & 63rd & 4th downs · 33% expected +12% MIA SEA: Punt
3 Q3 4:12 J. Sanders made 43-yard field goalKicks · 80% expected for him +9% MIA MIA: Field goal
4 Q4 14:19 The Dolphins converted 3rd & 73rd & 4th downs · 33% expected +8% MIA MIA: Field goal
5 Q4 13:03 The Dolphins fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +9% MIA MIA: Field goal
6 Q4 12:14 The Dolphins converted 3rd & 103rd & 4th downs · 27% expected +9% MIA MIA: Field goal
7 Q4 11:41 The Dolphins converted 3rd & 103rd & 4th downs · 27% expected +10% MIA MIA: Field goal
8 Q4 9:18 The Dolphins were stopped on 3rd & 33rd & 4th downs · 43% expected +15% SEA MIA: Field goal

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.

  • Vince Biegel (MIA LB), out (IR) · 0.2 pts
  • Jamal Adams (SEA SS), out · 0.6 pts
  • Quinton Dunbar (SEA CB), out · 0.5 pts
  • Rasheem Green (SEA DE), out (IR) · 0.3 pts
  • Bruce Irvin (SEA LB), out (IR) · 0.3 pts
  • Lano Hill (SEA SS), out · 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 91% · Dolphins 9%

Final margin
Seahawks by 8
Luck in points
1.5 for the Dolphins
Luck-adjusted margin
Seahawks by 9.5
Replay with same day's form
Seahawks 82% · Dolphins 18% 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 4 2020 games · Seahawks · Dolphins

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