luckadjusted

Week 7 2019 · October 20, 2019

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

Dolphins at Bills, Week 7 2019: who deserved to win?

The Bills beat the Dolphins 31–21, and it was no fluke: replayed with the way both teams actually played, the Bills win 8 of 10.

Before kickoff the Bills were 90% favorites. The biggest swing (Q2, 0:41 left): the Bills were stopped on 3rd & 19, worth 39 points of win probability to the Bills.

Final

Miami Dolphins 21
Buffalo Bills 31

October 20, 2019 · New Era Field · Closing line: Bills −17

Luck index +16 Bills 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, Bills win 8.

  1. 1 MIA 29 BUF 18
  2. 2 MIA 23 BUF 19
  3. 3 MIA 3 BUF 6
  4. 4 MIA 10 BUF 14
  5. 5 MIA 12 BUF 21
  6. 6 MIA 10 BUF 21
  7. 7 MIA 10 BUF 24
  8. 8 MIA 17 BUF 34
  9. 9 MIA 14 BUF 36
  10. 10 MIA 3 BUF 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 16% of them, Bills 84%, counting the 2% still level after regulation as half each. The line is what actually happened: Bills by 10.

Show as a table
Final margin in the replaysShare of replays
Dolphins by 17+0.9%
Dolphins by 9–163.3%
Dolphins by 1–810.1%
Level after regulation1.7%
Bills by 1–819.9%
Bills by 9–1624.9%
Bills by 17+39.1%

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 +1.1 points to the Dolphins: the final margin was Bills by 10, without the luck Bills by 11.1. 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.

  • S. Hauschka, 39 yds made · 88% expected
  • S. Hauschka, 43 yds made · 83% expected
  • S. Hauschka, 45 yds made · 79% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Dolphins 6 for 55 yards, Bills 9 for 83 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 14:29 Disqualification on the Dolphins (Christian Wilkins), 15 yards +1% BUF +1.8 pts
Q1 14:19 Offensive Holding on the Bills, 10 yards, wiping out the play +5% MIA +1.8 pts
Q1 12:20 Defensive Holding on the Dolphins (Eric Rowe), 5 yards +2% BUF +0.8 pts
Q1 4:34 Offensive Holding on the Bills, 10 yards +5% MIA +1.7 pts
Q1 2:05 Defensive Offside on the Bills (Darryl Johnson), 5 yards · pre-snap 0% BUF +0.2 pts
Q2 14:49 Offensive Holding on the Bills, 10 yards +4% MIA +1.5 pts
Q2 7:25 Roughing the Passer on the Bills (Shaq Lawson), 15 yards +3% MIA +1.2 pts
Q2 1:11 False Start on the Bills (Tyler Kroft), 5 yards · pre-snap +1% MIA +0.1 pts
Q3 15:00 Offensive Holding on the Dolphins, 10 yards +3% BUF +1.1 pts
Q3 9:24 Offensive Holding on the Dolphins, 10 yards, wiping out the play +7% BUF +2.3 pts
Q3 8:53 Roughing the Passer on the Bills, 12 yards +3% MIA +1.2 pts
Q4 15:00 Offensive Holding on the Bills (Dawson Knox), 10 yards +6% MIA +0.8 pts
Q4 6:27 Offensive Holding on the Dolphins, 10 yards, wiping out the play +7% BUF +3.6 pts
Q4 3:35 False Start on the Dolphins (Preston Williams), 5 yards · pre-snap +1% BUF +0.4 pts
Q4 3:33 Defensive Pass Interference on the Bills (Tremaine Edmunds), 6 yards +2% MIA +1.2 pts

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

When it happened

Bills’ chance of winning

As low as 17% 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 Bills were ahead in it, below while the Dolphins were.
#WhenWhat happenedWin probability forNext drive
1 Q2 15:00 The Dolphins converted 3rd & 13rd & 4th downs · 63% expected +9% MIA MIA: Touchdown
2 Q2 5:58 The Dolphins converted 3rd & 33rd & 4th downs · 48% expected +9% MIA MIA: Touchdown
3 Q2 0:41 The Bills were stopped on 3rd & 193rd & 4th downs · 18% expected +39% BUF BUF: End of half
4 Q3 14:16 The Dolphins converted 3rd & 93rd & 4th downs · 26% expected +8% MIA MIA: Turnover
5 Q3 9:24 Offensive Holding on the Dolphins, 10 yards, wiping out the playJudgment calls +7% BUF BUF: Touchdown
6 Q4 15:00 The Bills were stopped on 3rd & 13rd & 4th downs · 74% expectedOffensive Holding on the Bills (Dawson Knox), 10 yardsJudgment calls · 2 flags in 250 snaps before, position avg 1 per 253 +13% MIA BUF: Touchdown
7 Q4 14:30 The Bills converted 3rd & 73rd & 4th downs · 35% expected +7% BUF BUF: Touchdown
8 Q4 8:14 The Dolphins fumbled and the Bills recoveredFumble bounces · loose balls are close to 50/50 +10% BUF MIA: 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.

  • Matt Milano (BUF LB), out · 0.6 pts
  • Robert Foster (BUF WR), out · 0.4 pts
  • Xavien Howard (MIA CB), out · 1.2 pts
  • Reshad Jones (MIA FS), out · 0.5 pts
  • Daniel Kilgore (MIA C), out · 0.3 pts
  • Avery Moss (MIA DE), out · 0.2 pts
  • Danny Isidora (MIA G), 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 4% · Bills 96%

Final margin
Bills by 10
Luck in points
1.1 for the Dolphins
Luck-adjusted margin
Bills by 11.1
Replay with same day's form
Dolphins 16% · Bills 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 7 2019 games · Dolphins · Bills

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