luckadjusted

Week 18 2025 · January 4, 2026

Cardinals at Rams, Week 18 2025: who deserved to win?

The Rams beat the Cardinals 37–20, and it was no fluke: replayed with the way both teams actually played, the Rams win 9 of 10. The Cardinals had the bounces: kicks alone were worth 12 points of win probability to the Cardinals.

Before kickoff the Rams were 86% favorites. The biggest swing (Q3, 0:42 left): Illegal Blindside Block on the Cardinals, 10 yards, wiping out the play, worth 30 points of win probability to the Rams.

Final

Arizona Cardinals 20
Los Angeles Rams 37

January 4, 2026 · SoFi Stadium · Closing line: Rams −14.5

Luck index +8 Rams about even · −8 Cardinals

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. Cardinals win 1, Rams win 9.

  1. 1 ARI 31 LA 24
  2. 2 ARI 21 LA 24
  3. 3 ARI 23 LA 29
  4. 4 ARI 9 LA 19
  5. 5 ARI 17 LA 29
  6. 6 ARI 13 LA 27
  7. 7 ARI 6 LA 23
  8. 8 ARI 17 LA 37
  9. 9 ARI 9 LA 34
  10. 10 ARI 9 LA 40

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

Cardinals win 8% of them, Rams 92%, counting the 2% still level after regulation as half each. The line is what actually happened: Rams by 17.

Show as a table
Final margin in the replaysShare of replays
Cardinals by 17+0.6%
Cardinals by 9–161.5%
Cardinals by 1–85.9%
Level after regulation1.6%
Rams by 1–816.1%
Rams by 9–1621.7%
Rams by 17+52.7%

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 +11.8 points to the Rams: the final margin was Rams by 17, without the luck Rams by 5.2. 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.

  • H. Mevis, 34 yds made · 95% expected
  • C. Ryland, 45 yds made · 77% expected
  • H. Mevis, 42 yds made · 87% expected
  • C. Ryland, 56 yds made · 60% expected
  • H. Mevis, 40 yds made · 89% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Cardinals 6 for 45 yards, Rams 4 for 20 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 14:13 False Start on the Cardinals, 5 yards · pre-snap +1% LA +0.9 pts
Q1 5:30 Offensive Pass Interference on the Cardinals (Michael Wilson), 10 yards, wiping out the play +7% LA +2.4 pts
Q1 1:18 Illegal Shift on the Rams, 5 yards · pre-snap +2% ARI +1.1 pts
Q2 11:52 False Start on the Rams, 5 yards · pre-snap +1% ARI +0.5 pts
Q2 0:49 Defensive Offside on the Cardinals (Baron Browning), 5 yards, wiping out the play · pre-snap +5% LA +0.6 pts
Q3 14:20 False Start on the Rams (Xavier Smith), 5 yards · pre-snap +1% ARI +0.5 pts
Q3 13:41 Offensive Holding on the Cardinals (Pharaoh Brown), 10 yards, wiping out the play +4% LA +1.2 pts
Q3 7:56 Neutral Zone Infraction on the Rams (Braden Fiske), 5 yards · pre-snap +2% ARI +0.8 pts
Q3 0:42 Illegal Blindside Block on the Cardinals, 10 yards, wiping out the play +30% LA +6.3 pts
Q4 10:39 False Start on the Cardinals, 5 yards · pre-snap 0% LA +0.5 pts

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

When it happened

Rams’ chance of winning

As low as 37% 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 Cardinals were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:10 The Cardinals were stopped on 3rd & 73rd & 4th downs · 35% expectedThe Cardinals fumbled and the Rams recoveredFumble bounces · loose balls are close to 50/50 +17% LA ARI: Field goal
2 Q1 6:10 The Cardinals converted 3rd & 33rd & 4th downs · 53% expected +6% ARI ARI: Field goal
3 Q1 5:30 Offensive Pass Interference on the Cardinals (Michael Wilson), 10 yards, wiping out the playJudgment calls · 6 flags in 2412 snaps before, position avg 1 per 403 +7% LA LA: Field goal
4 Q2 9:40 C. Ryland made 56-yard field goalKicks · 60% expected for him, 20 of 34 from 45+ before +8% ARI ARI: Turnover
5 Q2 1:26 The Rams converted 4th & 23rd & 4th downs · 52% expected +8% LA LA: Touchdown
6 Q2 0:49 Defensive Offside on the Cardinals (Baron Browning), 5 yards, wiping out the playPre-snap flags · 18 flags in 2504 snaps before, position avg 1 per 445 +5% LA LA: Field goal
7 Q3 11:26 The Cardinals converted 4th & 83rd & 4th downs · 32% expected +8% ARI ARI: Touchdown
8 Q3 0:42 Illegal Blindside Block on the Cardinals, 10 yards, wiping out the playJudgment calls +30% LA LA: 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.

  • Davante Adams (LA WR), out · 0.9 pts
  • Rob Havenstein (LA OL), out (IR) · 0.6 pts
  • Kevin Dotson (LA OL), out · 0.5 pts
  • Quentin Lake (LA S), out (IR) · 0.2 pts
  • Garrett Williams (ARI CB), out (IR) · 0.7 pts
  • Marvin Harrison Jr. (ARI WR), out (IR) · 0.5 pts
  • Evan Brown (ARI OL), out · 0.4 pts
  • Greg Dortch (ARI WR), out (IR) · 0.4 pts
  • Will Hernandez (ARI OL), out (IR) · 0.4 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

Cardinals 31% · Rams 69%

Final margin
Rams by 17
Luck in points
11.8 for the Rams
Luck-adjusted margin
Rams by 5.2
Replay with same day's form
Cardinals 8% · Rams 92% 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 18 2025 games · Cardinals · Rams

More from Week 18 2025