luckadjusted

Week 8 2023 · October 29, 2023

Patriots at Dolphins, Week 8 2023: who deserved to win?

The Dolphins beat the Patriots 31–17, and it was no fluke: replayed with the way both teams actually played, the Dolphins win 10 of 10.

Before kickoff the Dolphins were 71% favorites. The biggest swing (Q1, 4:37 left): the Dolphins were stopped on 3rd & 15, worth 17 points of win probability to the Patriots.

Final

New England Patriots 17
Miami Dolphins 31

October 29, 2023 · Hard Rock Stadium · Closing line: Dolphins −7.5

Luck index +4 Dolphins about even · −4 Patriots

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. Patriots win 0, Dolphins win 10.

  1. 1 NE 31 MIA 34
  2. 2 NE 23 MIA 28
  3. 3 NE 20 MIA 28
  4. 4 NE 13 MIA 24
  5. 5 NE 21 MIA 35
  6. 6 NE 6 MIA 23
  7. 7 NE 3 MIA 23
  8. 8 NE 17 MIA 41
  9. 9 NE 14 MIA 41
  10. 10 NE 0 MIA 34

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

Patriots win 4% of them, Dolphins 96%, counting the 1% still level after regulation as half each. The line is what actually happened: Dolphins by 14.

Show as a table
Final margin in the replaysShare of replays
Patriots by 17+0.1%
Patriots by 9–160.8%
Patriots by 1–82.8%
Level after regulation0.5%
Dolphins by 1–88.6%
Dolphins by 9–1617.7%
Dolphins by 17+69.5%

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 +0.1 points to the Dolphins: the final margin was Dolphins by 14, without the luck Dolphins by 13.9. 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, 30 yds made · 95% expected
  • C. Ryland, 38 yds made · 86% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Patriots 7 for 45 yards, Dolphins 3 for 25 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
Q2 15:00 Offensive Holding on the Patriots (Kendrick Bourne), 10 yards, wiping out the play +4% MIA +1.2 pts
Q2 13:44 False Start on the Patriots, 5 yards · pre-snap +1% MIA +0.2 pts
Q2 13:35 Defensive Holding on the Patriots (Davon Godchaux), 5 yards 0% MIA +0.2 pts
Q2 6:22 Defensive Pass Interference on the Patriots, 5 yards +5% MIA +2.3 pts
Q2 1:01 Offensive Holding on the Dolphins (Durham Smythe), 10 yards +1% NE +1.3 pts
Q3 12:00 False Start on the Dolphins, 5 yards · pre-snap +1% NE +0.7 pts
Q3 4:09 Offensive Holding on the Dolphins, 10 yards, wiping out the play +2% NE +1.7 pts
Q3 2:26 Neutral Zone Infraction on the Patriots (Jack Jones), 5 yards · pre-snap 0% MIA +0.5 pts
Q4 12:19 Ineligible Downfield Pass on the Patriots, 5 yards +3% MIA +1.0 pts
Q4 2:00 Unsportsmanlike Conduct on the Patriots (JuJu Smith-Schuster), 10 yards 0% MIA +0.9 pts

Patriots penalties, every game · Dolphins penalties, every game · All teams, 2023

When it happened

Dolphins’ 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 Dolphins were ahead in it, below while the Patriots were.
#WhenWhat happenedWin probability forNext drive
1 Q1 12:02 The Dolphins converted 4th & 13rd & 4th downs · 71% expected +11% MIA MIA: Punt
2 Q1 4:37 The Dolphins were stopped on 3rd & 153rd & 4th downs · 19% expectedThe Dolphins threw an interception-worthy pass, and it was pickedInterceptions · 47% expected to stay out of the defense's hands +17% NE MIA: Touchdown
3 Q1 3:39 The Patriots converted 3rd & 43rd & 4th downs · 41% expected +9% NE NE: Touchdown
4 Q2 11:14 The Dolphins converted 4th & 43rd & 4th downs · 43% expected +12% MIA MIA: Touchdown
5 Q3 15:00 The Dolphins fumbled and the Patriots recoveredFumble bounces · loose balls are close to 50/50 +6% NE MIA: Touchdown
6 Q3 13:32 The Patriots were stopped on 3rd & 53rd & 4th downs · 37% expected +6% MIA NE: Field goal
7 Q3 10:52 The Dolphins converted 3rd & 93rd & 4th downs · 27% expected +5% MIA MIA: Touchdown
8 Q4 8:33 The Patriots converted 4th & 33rd & 4th downs · 39% expected +7% NE NE: 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.

  • Xavien Howard (MIA CB), out · 1.3 pts
  • Terron Armstead (MIA T), out (IR) · 0.8 pts
  • Connor Williams (MIA C), out · 0.6 pts
  • Jevon Holland (MIA SS), out · 0.5 pts
  • Isaiah Wynn (MIA G), out (IR) · 0.3 pts
  • Christian Gonzalez (NE CB), out (IR) · 1.0 pts
  • Vederian Lowe (NE T), out · 0.4 pts
  • Matt Judon (NE LB), out (IR) · 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

Patriots 1% · Dolphins 99%

Final margin
Dolphins by 14
Luck in points
0.1 for the Dolphins
Luck-adjusted margin
Dolphins by 13.9
Replay with same day's form
Patriots 4% · Dolphins 96% 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 8 2023 games · Patriots · Dolphins

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