luckadjusted

Week 15 2025 · December 15, 2025

Dolphins at Steelers, Week 15 2025: who deserved to win?

The Steelers beat the Dolphins 28–15 and were the better team on the day: replayed with the same form, they win 6 of 10.

Before kickoff the Steelers were 59% favorites. The biggest swing (Q2, 11:04 left): Offensive Holding on the Steelers (Jonnu Smith), 10 yards, wiping out the play, worth 10 points of win probability to the Dolphins.

Final

Miami Dolphins 15
Pittsburgh Steelers 28

December 15, 2025 · Acrisure Stadium · Closing line: Steelers −3

Luck index +39 Steelers lucky · −39 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 4, Steelers win 6.

  1. 1 MIA 35 PIT 16
  2. 2 MIA 21 PIT 10
  3. 3 MIA 31 PIT 24
  4. 4 MIA 24 PIT 21
  5. 5 MIA 17 PIT 19
  6. 6 MIA 16 PIT 20
  7. 7 MIA 28 PIT 35
  8. 8 MIA 10 PIT 20
  9. 9 MIA 7 PIT 23
  10. 10 MIA 10 PIT 33

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 39% of them, Steelers 61%, counting the 3% still level after regulation as half each. The line is what actually happened: Steelers by 13.

Show as a table
Final margin in the replaysShare of replays
Dolphins by 17+6.7%
Dolphins by 9–1611.8%
Dolphins by 1–819.6%
Level after regulation3.4%
Steelers by 1–827.9%
Steelers by 9–1616.2%
Steelers by 17+14.5%

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 +1.2 points to the Dolphins: the final margin was Steelers by 13, without the luck Steelers by 14.2. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Dolphins 6 for 31 yards, Steelers 4 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 11:25 Delay of Game on the Dolphins, 4 yards · pre-snap +2% PIT +0.7 pts
Q2 11:04 Offensive Holding on the Steelers (Jonnu Smith), 10 yards, wiping out the play +10% MIA +2.7 pts
Q2 5:11 Kickoff Short of Landing Zone on the Dolphins (Riley Patterson), 0 yards · pre-snap 0% PIT 0.0 pts
Q2 1:21 Face Mask on the Dolphins (Jordyn Brooks), 2 yards +2% PIT +0.6 pts
Q3 11:20 Kickoff Short of Landing Zone on the Steelers (Chris Boswell), 0 yards · pre-snap 0% MIA 0.0 pts
Q3 8:26 Defensive Too Many Men on Field on the Dolphins, 5 yards · pre-snap +1% PIT +1.2 pts
Q3 3:24 Illegal Block Above the Waist on the Steelers (Ben Skowronek), 10 yards 0% MIA +0.6 pts
Q3 2:23 Taunting on the Dolphins (Jordyn Brooks), 15 yards 0% PIT +2.4 pts
Q3 0:28 Illegal Shift on the Steelers (Pat Freiermuth), 5 yards · pre-snap 0% MIA +1.2 pts
Q4 0:42 Delay of Game on the Dolphins, 5 yards · pre-snap 0% PIT +0.1 pts

Dolphins penalties, every game · Steelers penalties, every game · All teams, 2025

When it happened

Steelers’ chance of winning

As low as 47% 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 Steelers were ahead in it, below while the Dolphins were.
#WhenWhat happenedWin probability forNext drive
1 Q1 2:19 The Steelers converted 4th & 33rd & 4th downs · 51% expected +9% PIT PIT: Punt
2 Q1 0:19 The Steelers were stopped on 3rd & 113rd & 4th downs · 25% expected +7% MIA PIT: Punt
3 Q2 11:04 Offensive Holding on the Steelers (Jonnu Smith), 10 yards, wiping out the playJudgment calls · 22 flags in 4468 snaps before, position avg 1 per 278 +10% MIA MIA: Field goal
4 Q2 9:19 The Steelers were stopped on 3rd & 33rd & 4th downs · 51% expected +7% MIA PIT: Punt
5 Q2 7:46 The Dolphins converted 3rd & 63rd & 4th downs · 38% expected +9% MIA MIA: Field goal
6 Q2 5:34 The Dolphins were stopped on 3rd & 13rd & 4th downs · 74% expected +7% PIT MIA: Field goal
7 Q2 0:21 The Steelers converted 3rd & 13rd & 4th downs · 66% expected +9% PIT PIT: Touchdown
8 Q3 5:06 The Steelers converted 3rd & 123rd & 4th downs · 24% expected +7% PIT PIT: 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.

  • Broderick Jones (PIT T), out (IR) · 0.8 pts
  • T.J. Watt (PIT LB), out · 0.7 pts
  • James Pierre (PIT CB), out · 0.4 pts
  • Andrus Peat (PIT G), out · 0.3 pts
  • DeShon Elliott (PIT S), out (IR) · 0.3 pts
  • Derrick Harmon (PIT DT), out · 0.1 pts
  • Larry Borom (MIA OL), out · 0.3 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 1% · Steelers 99%

Final margin
Steelers by 13
Luck in points
1.2 for the Dolphins
Luck-adjusted margin
Steelers by 14.2
Replay with same day's form
Dolphins 39% · Steelers 61% 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 15 2025 games · Dolphins · Steelers

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