luckadjusted

Week 1 2020 · September 13, 2020

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

Dolphins at Patriots, Week 1 2020: who deserved to win?

The Patriots beat the Dolphins 21–11, and it was no fluke: replayed with the way both teams actually played, the Patriots win 8 of 10. The Dolphins had the bounces: kicks alone were worth 9 points of win probability to the Dolphins.

Before kickoff the Patriots were 71% favorites.

Final

Miami Dolphins 11
New England Patriots 21

September 13, 2020 · Gillette Stadium · Closing line: Patriots −7.5

Luck index +16 Patriots about even · −16 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. Dolphins win 2, Patriots win 8.

  1. 1 MIA 16 NE 6
  2. 2 MIA 30 NE 27
  3. 3 MIA 17 NE 19
  4. 4 MIA 20 NE 24
  5. 5 MIA 20 NE 27
  6. 6 MIA 13 NE 23
  7. 7 MIA 10 NE 23
  8. 8 MIA 14 NE 30
  9. 9 MIA 0 NE 20
  10. 10 MIA 0 NE 26

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

Dolphins win 16% of them, Patriots 84%, counting the 2% still level after regulation as half each. The line is what actually happened: Patriots by 10.

Show as a table
Final margin in the replaysShare of replays
Dolphins by 17+1.1%
Dolphins by 9–164.3%
Dolphins by 1–810.5%
Level after regulation2.3%
Patriots by 1–827.5%
Patriots by 9–1622.7%
Patriots by 17+31.6%

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 +6.4 points to the Dolphins: the final margin was Patriots by 10, without the luck Patriots by 16.4. 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, 46 yds made · 75% expected
  • N. Folk, 45 yds missed · 78% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Dolphins 4 for 35 yards, Patriots 3 for 47 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 0:49 Offensive Holding on the Dolphins, 10 yards +3% NE +0.9 pts
Q3 1:07 Roughing the Passer on the Dolphins (Brandon Jones), 10 yards 0% NE +0.4 pts
Q4 14:16 Defensive Pass Interference on the Patriots (Stephon Gilmore), 23 yards +6% MIA +3.8 pts
Q4 11:53 Defensive Pass Interference on the Patriots (Terrence Brooks), 5 yards +3% MIA +0.8 pts
Q4 10:31 Unnecessary Roughness on the Dolphins (Jerome Baker), 15 yards +6% NE +1.8 pts
Q4 6:08 Unsportsmanlike Conduct on the Dolphins (Jerome Baker), 0 yards +1% NE +0.4 pts
Q4 3:30 Defensive Pass Interference on the Patriots (Stephon Gilmore), 19 yards +2% MIA +2.3 pts

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

When it happened

Patriots’ chance of winning

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 Patriots were ahead in it, below while the Dolphins were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:06 The Patriots fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +6% NE NE: Punt
2 Q1 6:51 The Dolphins fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +7% MIA MIA: Punt
3 Q1 6:13 The Dolphins converted 3rd & 23rd & 4th downs · 59% expected +6% MIA MIA: Punt
4 Q2 11:47 The Dolphins were stopped on 3rd & 113rd & 4th downs · 24% expected +7% NE MIA: Field goal
5 Q2 0:49 The Dolphins were stopped on 3rd & 23rd & 4th downs · 58% expectedOffensive Holding on the Dolphins, 10 yardsJudgment calls +5% NE MIA: Turnover
6 Q2 0:06 N. Folk missed 45-yard field goalKicks · 78% expected for him, 2 of 4 from 45+ before +7% MIA NE: Touchdown
7 Q4 14:16 Defensive Pass Interference on the Patriots (Stephon Gilmore), 23 yardsJudgment calls · 5 flags in 1011 snaps before, position avg 1 per 237 +6% MIA MIA: Touchdown
8 Q4 10:35 The Dolphins converted 3rd & 13rd & 4th downs · 64% expected +6% MIA MIA: 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.

  • Vince Biegel (MIA 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

Dolphins 0% · Patriots 100%

Final margin
Patriots by 10
Luck in points
6.4 for the Dolphins
Luck-adjusted margin
Patriots by 16.4
Replay with same day's form
Dolphins 16% · Patriots 84% 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 1 2020 games · Dolphins · Patriots

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