luckadjusted

Week 17 2019 · December 29, 2019

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

Dolphins at Patriots, Week 17 2019: who deserved to win?

The Dolphins beat the Patriots 27–24, but it was a coin flip: replayed with the way both teams played, the Dolphins win 4 of 10. Luck ran their way: judgment calls alone were worth 29 points of win probability to the Dolphins.

Before kickoff the Patriots were 90% favorites. The biggest swing (Q4, 0:24 left): Unnecessary Roughness on the Patriots (Danny Shelton), 15 yards, worth 29 points of win probability to the Dolphins.

Final

Miami Dolphins 27
New England Patriots 24

December 29, 2019 · Gillette Stadium · Closing line: Patriots −17.5

Luck index +57 Dolphins lucky · −57 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. Dolphins win 4, Patriots win 6.

  1. 1 MIA 34 NE 13
  2. 2 MIA 27 NE 17
  3. 3 MIA 16 NE 10
  4. 4 MIA 14 NE 12
  5. 5 MIA 14 NE 16
  6. 6 MIA 14 NE 20
  7. 7 MIA 16 NE 24
  8. 8 MIA 10 NE 22
  9. 9 MIA 17 NE 33
  10. 10 MIA 10 NE 31

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 43% of them, Patriots 57%, counting the 3% still level after regulation as half each. The line is what actually happened: Dolphins by 3.

Show as a table
Final margin in the replaysShare of replays
Dolphins by 17+7.4%
Dolphins by 9–1613.6%
Dolphins by 1–819.7%
Level after regulation2.8%
Patriots by 1–826.4%
Patriots by 9–1615.9%
Patriots by 17+14.4%

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 +0.7 points to the Dolphins: the final margin was Dolphins by 3, without the luck Dolphins by 2.4. 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, 27 yds made · 97% expected
  • N. Folk, 25 yds made · 98% expected
  • J. Sanders, 32 yds made · 95% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Dolphins 4 for 35 yards, Patriots 6 for 54 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 0:06 Offensive Pass Interference on the Patriots (Ben Watson), 10 yards, wiping out the play +7% MIA +2.4 pts
Q2 9:50 Defensive Pass Interference on the Dolphins, 10 yards +6% NE +2.2 pts
Q2 3:52 Unnecessary Roughness on the Dolphins (Jerome Baker), 15 yards +6% NE +1.9 pts
Q3 9:25 Offensive Too Many Men on Field on the Dolphins, 5 yards · pre-snap +3% NE +0.7 pts
Q3 4:26 Horse Collar Tackle on the Patriots (Deatrich Wise Jr.), 15 yards +4% MIA +1.3 pts
Q3 0:23 Delay of Game on the Dolphins, 5 yards · pre-snap +6% NE +0.2 pts
Q4 12:56 Illegal Shift on the Patriots, 5 yards, wiping out the play · pre-snap +11% MIA +2.2 pts
Q4 9:30 Defensive Pass Interference on the Patriots, 4 yards +2% MIA +0.6 pts
Q4 3:59 False Start on the Patriots (Ben Watson), 5 yards · pre-snap +6% MIA +0.5 pts
Q4 0:24 Unnecessary Roughness on the Patriots (Danny Shelton), 15 yards +29% MIA +1.3 pts

Dolphins penalties, every game · Patriots penalties, every game · All teams, 2019

When it happened

Patriots’ chance of winning

As low as 0% and as high as 78%. 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 Q2 10:41 Return touchdown by the DolphinsSpecial teams +21% MIA MIA: Opp touchdown
2 Q3 11:00 The Dolphins converted 3rd & 23rd & 4th downs · 60% expected +9% MIA MIA: Touchdown
3 Q4 12:56 Illegal Shift on the Patriots, 5 yards, wiping out the playPre-snap flags +11% MIA MIA: Field goal
4 Q4 5:37 The Patriots converted 3rd & 43rd & 4th downs · 45% expected +18% NE NE: Touchdown
5 Q4 3:59 The Patriots converted 3rd & 133rd & 4th downs · 23% expectedFalse Start on the Patriots (Ben Watson), 5 yardsPre-snap flags · 2 flags in 427 snaps before, position avg 1 per 253 +15% NE NE: Touchdown
6 Q4 2:16 The Dolphins fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +17% MIA MIA: Touchdown
7 Q4 0:24 Unnecessary Roughness on the Patriots (Danny Shelton), 15 yardsJudgment calls · 3 flags in 559 snaps before, position avg 1 per 242 +29% MIA –
8 Q4 0:02 The Patriots were stopped on 3rd & 103rd & 4th downs · 27% expectedThe Patriots fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +14% MIA –

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.

  • Jason McCourty (NE CB), out · 0.5 pts
  • Allen Hurns (MIA WR), out · 0.6 pts
  • Bobby McCain (MIA FS), out (IR) · 0.4 pts
  • Ryan Lewis (MIA CB), out (IR) · 0.3 pts
  • Ken Webster (MIA CB), out (IR) · 0.2 pts
  • Taco Charlton (MIA DE), out · 0.2 pts
  • Vince Biegel (MIA LB), out · 0.2 pts
  • Raekwon McMillan (MIA LB), out (IR) · 0.1 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 56% · Patriots 44%

Final margin
Dolphins by 3
Luck in points
0.7 for the Dolphins
Luck-adjusted margin
Dolphins by 2.3
Replay with same day's form
Dolphins 43% · Patriots 57% 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 17 2019 games · Dolphins · Patriots

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