luckadjusted

Week 15 2025 · December 14, 2025

Lions at Rams, Week 15 2025: who deserved to win?

The Rams beat the Lions 41–34, and it was no fluke: replayed with the way both teams actually played, the Rams win 8 of 10.

Before kickoff the Rams were 66% favorites. The biggest swing (Q1, 1:53 left): the Lions converted 3rd & 8, worth 13 points of win probability to the Lions.

Final

Detroit Lions 34
Los Angeles Rams 41

December 14, 2025 · SoFi Stadium · Closing line: Rams −5.5

Luck index +16 Rams about even · −16 Lions

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. Lions win 2, Rams win 8.

  1. 1 DET 34 LA 23
  2. 2 DET 51 LA 48
  3. 3 DET 17 LA 19
  4. 4 DET 27 LA 31
  5. 5 DET 27 LA 34
  6. 6 DET 16 LA 27
  7. 7 DET 19 LA 34
  8. 8 DET 30 LA 48
  9. 9 DET 14 LA 37
  10. 10 DET 13 LA 45

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

Lions win 16% of them, Rams 84%, counting the 2% still level after regulation as half each. The line is what actually happened: Rams by 7.

Show as a table
Final margin in the replaysShare of replays
Lions by 17+1.5%
Lions by 9–163.5%
Lions by 1–89.1%
Level after regulation1.7%
Rams by 1–820.7%
Rams by 9–1621.3%
Rams by 17+42.1%

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 +10.0 points to the Rams: the final margin was Rams by 7, without the luck Lions by 3. 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. Bates, 43 yds missed · 86% expected
  • J. Bates, 24 yds made · 99% expected
  • H. Mevis, 37 yds made · 92% expected
  • H. Mevis, 44 yds made · 84% expected
  • J. Bates, 48 yds made · 78% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Lions 4 for 25 yards, Rams 2 for 8 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 13:06 Offensive Holding on the Lions, 10 yards +2% LA +0.9 pts
Q1 6:33 Defensive Holding on the Lions (Erick Hallett), 5 yards +1% LA +0.5 pts
Q2 8:45 Defensive Holding on the Lions (Alex Anzalone), 0 yards +3% LA +0.6 pts
Q3 8:33 Offensive Holding on the Lions (Giovanni Ricci), 10 yards, wiping out the play +8% LA +2.6 pts
Q4 2:50 Defensive Pass Interference on the Rams (Emmanuel Forbes), 3 yards +2% DET +3.6 pts
Q4 0:23 Delay of Game on the Rams, 5 yards · pre-snap 0% LA +0.2 pts

Lions penalties, every game · Rams penalties, every game · All teams, 2025

When it happened

Rams’ chance of winning

As low as 24% 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 Rams were ahead in it, below while the Lions were.
#WhenWhat happenedWin probability forNext drive
1 Q1 11:16 J. Bates missed 43-yard field goalKicks · 86% expected for him +11% LA DET: Touchdown
2 Q1 4:14 The Rams converted 4th & 83rd & 4th downs · 31% expected +9% LA LA: Touchdown
3 Q1 1:53 The Lions converted 3rd & 83rd & 4th downs · 32% expected +13% DET DET: Field goal
4 Q2 2:00 The Lions converted 4th & 13rd & 4th downs · 73% expected +8% DET DET: Touchdown
5 Q2 1:04 The Lions converted 3rd & 83rd & 4th downs · 32% expected +9% DET DET: Touchdown
6 Q3 11:14 The Rams converted 4th & 13rd & 4th downs · 72% expected +8% LA LA: Field goal
7 Q3 8:33 Offensive Holding on the Lions (Giovanni Ricci), 10 yards, wiping out the playJudgment calls · 0 flags in 984 snaps before, position avg 1 per 278 +8% LA LA: Touchdown
8 Q4 10:34 The Lions converted 4th & 13rd & 4th downs · 73% expected +8% DET DET: Field goal

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.

  • Rob Havenstein (LA OL), out (IR) · 0.6 pts
  • Tyler Higbee (LA TE), out (IR) · 0.5 pts
  • Quentin Lake (LA S), out (IR) · 0.3 pts
  • Sam LaPorta (DET TE), out (IR) · 1.2 pts
  • Brian Branch (DET DB), out (IR) · 0.8 pts
  • Thomas Harper (DET S), out · 0.4 pts
  • Kayode Awosika (DET G), out · 0.3 pts
  • Brock Wright (DET TE), out (IR) · 0.3 pts
  • Christian Mahogany (DET OL), out (IR) · 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

Lions 60% · Rams 40%

Final margin
Rams by 7
Luck in points
10.0 for the Rams
Luck-adjusted margin
Lions by 3.0
Replay with same day's form
Lions 16% · Rams 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 15 2025 games · Lions · Rams

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