luckadjusted
NFL Week 9 · 2026

Week 2 2024 · September 12, 2024

Bills at Dolphins, Week 2 2024: who deserved to win?

The Bills beat the Dolphins 31–10, and the replays back it up: with the way both teams actually played, the Bills win 8 of 10.

Before kickoff the Dolphins were 57% favorites.

Final

Buffalo Bills 31
Miami Dolphins 10

September 12, 2024 · Hard Rock Stadium · Closing line: Dolphins −2.5

Luck index +20 Bills about even · −20 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. Bills win 8, Dolphins win 2.

  1. 1 BUF 35 MIA 6
  2. 2 BUF 28 MIA 7
  3. 3 BUF 33 MIA 17
  4. 4 BUF 27 MIA 14
  5. 5 BUF 37 MIA 27
  6. 6 BUF 20 MIA 13
  7. 7 BUF 20 MIA 14
  8. 8 BUF 16 MIA 14
  9. 9 BUF 13 MIA 17
  10. 10 BUF 10 MIA 24

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

Bills win 80% of them, Dolphins 20%, counting the 2% still level after regulation as half each. The line is what actually happened: Bills by 21.

Show as a table
Final margin in the replaysShare of replays
Bills by 17+29.0%
Bills by 9–1622.3%
Bills by 1–827.3%
Level after regulation2.5%
Dolphins by 1–811.2%
Dolphins by 9–165.6%
Dolphins by 17+2.1%

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 +1.4 points to the Bills: the final margin was Bills by 21, without the luck Bills by 19.6. 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.

  • T. Bass, 43 yds made · 84% expected
  • J. Sanders, 34 yds made · 94% expected
  • T. Bass, 45 yds missed · 82% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Bills 1 for 5 yards, Dolphins 7 for 50 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 half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued

WhenFlagWin probability for
Q1 7:56 False Start on the Dolphins (Julian Hill), 5 yards · pre-snap +1% BUF +0.5 pts
Q1 4:18 False Start on the Dolphins, 5 yards · pre-snap +2% BUF +0.7 pts
Q2 12:06 Offensive Holding on the Dolphins, 10 yards, wiping out the play +8% BUF +2.1 pts
Q2 10:13 Unnecessary Roughness on the Dolphins (Jordan Poyer), 15 yards +5% BUF +1.8 pts
Q2 8:01 False Start on the Bills, 5 yards · pre-snap +1% MIA +0.5 pts
Q3 15:00 Illegal Formation on the Dolphins (Anthony Walker), 5 yards · pre-snap 0% BUF +0.5 pts
Q4 11:55 False Start on the Dolphins, 5 yards · pre-snap 0% BUF +0.5 pts
Q4 7:54 False Start on the Dolphins, 5 yards · pre-snap 0% BUF +0.4 pts

Bills penalties, every game · Dolphins penalties, every game · All teams, 2024

When it happened

Dolphins’ chance of winning

As low as 0% and as high as 57%. 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 Bills were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:55 The Bills converted 4th & 33rd & 4th downs · 57% expected +7% BUF BUF: Touchdown
2 Q1 5:03 The Dolphins converted 3rd & 43rd & 4th downs · 48% expected +6% MIA MIA: Touchdown
3 Q2 14:22 The Bills converted 3rd & 53rd & 4th downs · 45% expected +6% BUF BUF: Field goal
4 Q2 12:06 Offensive Holding on the Dolphins, 10 yards, wiping out the playJudgment calls +8% BUF BUF: Touchdown
5 Q2 10:13 Unnecessary Roughness on the Dolphins (Jordan Poyer), 15 yardsJudgment calls · 13 flags in 6037 snaps before, position avg 1 per 462 +5% BUF BUF: Touchdown
6 Q2 7:11 The Bills converted 3rd & 123rd & 4th downs · 28% expected +5% BUF BUF: Touchdown
7 Q2 3:50 The Dolphins were stopped on 4th & 23rd & 4th downs · 63% expected +6% BUF MIA: Field goal
8 Q3 9:37 The Dolphins threw an interception-worthy pass, and it was pickedInterceptions · defenses catch 56% of interception-worthy throwsReturn touchdown by the BillsSpecial teams +8% BUF MIA: Turnover on downs

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.

  • Bradley Chubb (MIA LB), out (IR) · 0.4 pts
  • Taron Johnson (BUF CB), out · 0.8 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

Bills 100% · Dolphins 0%

Final margin
Bills by 21
Luck in points
1.4 for the Bills
Luck-adjusted margin
Bills by 19.6
Replay with same day's form
Bills 80% · Dolphins 20% unchanged: why
How much of each is luck?

0% treats it as skill, 100% as pure luck. The tick is our fit.

What counts

None by default: our tests measured no carryover after a lucky break. Slide it up to count a break for more than its own swing. 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 2 2024 games · Bills · Dolphins

More from Week 2 2024