luckadjusted

Week 15 2023 · December 17, 2023

Commanders at Rams, Week 15 2023: who deserved to win?

The Rams beat the Commanders 28–20 and were the better team on the day: replayed with the same form, they win 8 of 10.

Before kickoff the Rams were 68% favorites. The biggest swing (Q1, 2:54 left): the Commanders converted 4th & 2, worth 14 points of win probability to the Commanders.

Final

Washington Commanders 20
Los Angeles Rams 28

December 17, 2023 · SoFi Stadium · Closing line: Rams −6.5

Luck index +25 Rams about even · −25 Commanders

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. Commanders win 2, Rams win 8.

  1. 1 WAS 40 LA 24
  2. 2 WAS 38 LA 33
  3. 3 WAS 40 LA 42
  4. 4 WAS 10 LA 14
  5. 5 WAS 16 LA 23
  6. 6 WAS 10 LA 20
  7. 7 WAS 17 LA 30
  8. 8 WAS 9 LA 26
  9. 9 WAS 27 LA 50
  10. 10 WAS 3 LA 34

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

Commanders win 25% of them, Rams 75%, counting the 2% still level after regulation as half each. The line is what actually happened: Rams by 8.

Show as a table
Final margin in the replaysShare of replays
Commanders by 17+3.9%
Commanders by 9–167.0%
Commanders by 1–812.7%
Level after regulation2.3%
Rams by 1–824.9%
Rams by 9–1620.1%
Rams by 17+29.1%

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 +4.1 points to the Commanders: the final margin was Rams by 8, without the luck Rams by 12.1. 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.

  • L. Havrisik, 22 yds made · 99% expected
  • L. Havrisik, 27 yds made · 98% expected
  • L. Havrisik, 43 yds missed · 85% expected
  • Extra point missed · 95% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Commanders 3 for 28 yards, Rams 5 for 36 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 14:11 False Start on the Rams (Tyler Higbee), 5 yards · pre-snap +1% WAS +1.0 pts
Q1 4:35 Offensive Holding on the Commanders, 10 yards, wiping out the play +6% LA +2.1 pts
Q2 0:27 Roughing the Passer on the Commanders (Daron Payne), 8 yards +2% LA +2.0 pts
Q3 2:07 Delay of Game on the Rams, 5 yards · pre-snap 0% WAS +0.5 pts
Q4 12:30 Unnecessary Roughness on the Rams, 15 yards 0% WAS +1.4 pts
Q4 9:05 Illegal Use of Hands on the Rams, 5 yards 0% WAS +0.9 pts
Q4 3:18 Offensive Pass Interference on the Commanders (Logan Thomas), 10 yards, wiping out the play +6% LA +3.0 pts
Q4 2:31 Defensive Pass Interference on the Rams (Derion Kendrick), 6 yards +1% WAS +2.8 pts

Commanders penalties, every game · Rams penalties, every game · All teams, 2023

When it happened

Rams’ chance of winning

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 Commanders were.
#WhenWhat happenedWin probability forNext drive
1 Q1 12:56 The Rams converted 3rd & 93rd & 4th downs · 29% expected +7% LA LA: Field goal
2 Q1 8:24 The Rams were stopped on 3rd & 33rd & 4th downs · 43% expected +5% WAS LA: Field goal
3 Q1 4:35 Offensive Holding on the Commanders, 10 yards, wiping out the playJudgment calls +6% LA LA: Turnover
4 Q1 2:54 The Commanders converted 4th & 23rd & 4th downs · 57% expected +14% WAS WAS: Turnover on downs
5 Q1 0:40 The Commanders were stopped on 4th & 13rd & 4th downs · 71% expected +13% LA WAS: Punt
6 Q2 15:00 The Rams converted 3rd & 63rd & 4th downs · 36% expected +5% LA LA: Turnover
7 Q2 13:11 The Rams converted 3rd & 53rd & 4th downs · 40% expected +5% LA LA: Turnover
8 Q4 3:18 Offensive Pass Interference on the Commanders (Logan Thomas), 10 yards, wiping out the playJudgment calls · 15 flags in 3269 snaps before, position avg 1 per 286 +6% LA LA: End of game

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 T), out · 1.0 pts
  • Tutu Atwell (LA WR), out · 0.3 pts
  • Alex Ward (LA LS), out (IR) · 0.1 pts
  • Jamin Davis (WAS LB), 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

Commanders 10% · Rams 90%

Final margin
Rams by 8
Luck in points
4.1 for the Commanders
Luck-adjusted margin
Rams by 12.1
Replay with same day's form
Commanders 25% · Rams 75% 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 2023 games · Commanders · Rams

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